diff --git a/packages/hydrooj/src/handler/contest.ts b/packages/hydrooj/src/handler/contest.ts
index 3d7826ad1..4b2e4037d 100644
--- a/packages/hydrooj/src/handler/contest.ts
+++ b/packages/hydrooj/src/handler/contest.ts
@@ -169,7 +169,7 @@ export class ContestDetailHandler extends ContestDetailBaseHandler {
             && !this.user.own(this.tdoc)
             && !this.user.hasPerm(PERM.PERM_VIEW_CONTEST_HIDDEN_SCOREBOARD)
         ) return;
-        const pdict = await problem.getList(domainId, this.tdoc.pids, true, undefined, undefined, problem.PROJECTION_CONTEST_LIST);
+        const pdict = await problem.getList(domainId, this.tdoc.pids, true, true, problem.PROJECTION_CONTEST_LIST);
         let psdict = {};
         let rdict = {};
         if (this.tsdoc) {
@@ -252,7 +252,7 @@ export class ContestScoreboardHandler extends ContestDetailBaseHandler {
         const tdoc = await contest.get(domainId, tid);
         if (!contest.canShowScoreboard.call(this, tdoc)) throw new ContestScoreboardHiddenError(tid);
         const [pdict, teams] = await Promise.all([
-            problem.getList(domainId, tdoc.pids, true, undefined, false, undefined, true),
+            problem.getList(domainId, tdoc.pids, true, false, undefined, true),
             contest.getMultiStatus(domainId, { docId: tid }).toArray(),
         ]);
         const udict = await user.getList(domainId, teams.map((i) => i.uid));
@@ -373,7 +373,7 @@ export class ContestEditHandler extends Handler {
         if (beginAtMoment.isSameOrAfter(endAt)) throw new ValidationError('duration');
         const beginAt = beginAtMoment.toDate();
         const lockAt = lock ? moment(endAt).add(-lock, 'minutes').toDate() : null;
-        await problem.getList(domainId, pids, this.user.hasPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN) || this.user._id, this.user.group, true);
+        await problem.getList(domainId, pids, this.user.hasPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN) || this.user._id, true);
         if (tid) {
             await contest.edit(domainId, tid, {
                 title, content, rule, beginAt, endAt, pids, rated, duration: contestDuration,
diff --git a/packages/hydrooj/src/handler/problem.ts b/packages/hydrooj/src/handler/problem.ts
index 9d92e9ec2..29581f3dc 100644
--- a/packages/hydrooj/src/handler/problem.ts
+++ b/packages/hydrooj/src/handler/problem.ts
@@ -64,7 +64,6 @@ registerValue('Problem', [
     ['difficulty', 'Int'],
     ['tag', '[String]'],
     ['hidden', 'Boolean'],
-    ['assign', '[String]'],
 ]);
 
 registerResolver(
@@ -74,11 +73,6 @@ registerResolver(
         const pdoc = await problem.get(ctx.args.domainId, arg.pid || arg.id);
         if (!pdoc) return null;
         if (pdoc.hidden) ctx.checkPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN);
-        if (pdoc.assign.length && !ctx.user.own(pdoc)) {
-            if (!Set.intersection(new Set(pdoc.assign), new Set(ctx.user.group)).size) {
-                throw new PermissionError(PERM.PERM_VIEW_PROBLEM_HIDDEN);
-            }
-        }
         ctx.pdoc = pdoc;
         return pdoc;
     },
@@ -86,7 +80,7 @@ registerResolver(
 registerResolver('Query', 'problems(ids: [Int])', '[Problem]', async (arg, ctx) => {
     ctx.checkPerm(PERM.PERM_VIEW);
     const res = await problem.getList(ctx.args.domainId, arg.ids, ctx.user.hasPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN) || ctx.user._id,
-        ctx.user.group, undefined, undefined, true);
+        undefined, undefined, true);
     return Object.keys(res).map((id) => res[+id]);
 }, 'Get a list of problem by ids');
 registerResolver(
@@ -105,7 +99,7 @@ registerResolver(
     },
 );
 registerResolver(
-    'ProblemManage', 'edit(title: String, content: String, tag: [String], hidden: Boolean, assign: [String])', 'Problem!',
+    'ProblemManage', 'edit(title: String, content: String, tag: [String], hidden: Boolean)', 'Problem!',
     (arg, ctx) => problem.edit(ctx.args.domainId, ctx.pdoc.docId, arg),
 );
 
@@ -640,14 +634,13 @@ export class ProblemEditHandler extends ProblemManageHandler {
     @post('hidden', Types.Boolean)
     @post('tag', Types.Content, true, null, parseCategory)
     @post('difficulty', Types.PositiveInt, (i) => +i <= 10, true)
-    @post('assign', Types.CommaSeperatedArray, true)
     async post(
         domainId: string, pid: string | number, title: string, content: string,
-        newPid: string = '', hidden = false, tag: string[] = [], difficulty = 0, assign: string[] = [],
+        newPid: string = '', hidden = false, tag: string[] = [], difficulty = 0,
     ) {
         if (newPid !== this.pdoc.pid && await problem.get(domainId, newPid)) throw new BadRequestError('new pid exists');
         const $update: Partial<ProblemDoc> = {
-            title, content, pid: newPid, hidden, assign, tag: tag ?? [], difficulty, html: false,
+            title, content, pid: newPid, hidden, tag: tag ?? [], difficulty, html: false,
         };
         const pdoc = await problem.edit(domainId, this.pdoc.docId, $update);
         this.response.redirect = this.url('problem_detail', { pid: newPid || pdoc.docId });
@@ -972,13 +965,12 @@ export class ProblemCreateHandler extends Handler {
     @post('hidden', Types.Boolean)
     @post('difficulty', Types.PositiveInt, (i) => +i <= 10, true)
     @post('tag', Types.Content, true, null, parseCategory)
-    @post('assign', Types.CommaSeperatedArray, true)
     async post(
         domainId: string, title: string, content: string, pid: string,
-        hidden = false, difficulty = 0, tag: string[] = [], assign: string[] = [],
+        hidden = false, difficulty = 0, tag: string[] = [],
     ) {
         if (pid && await problem.get(domainId, pid)) throw new BadRequestError('ProblemID already exists');
-        const docId = await problem.add(domainId, pid, title, content, this.user._id, tag ?? [], hidden, assign);
+        const docId = await problem.add(domainId, pid, title, content, this.user._id, tag ?? [], hidden);
         const files = new Set(Array.from(content.matchAll(/file:\/\/([a-zA-Z0-9_-]+\.[a-zA-Z0-9]+)/g)).map((i) => i[1]));
         const tasks = [];
         for (const file of files) {
diff --git a/packages/hydrooj/src/handler/record.ts b/packages/hydrooj/src/handler/record.ts
index f81dafc37..36087dc74 100644
--- a/packages/hydrooj/src/handler/record.ts
+++ b/packages/hydrooj/src/handler/record.ts
@@ -89,7 +89,7 @@ class RecordListHandler extends ContestDetailBaseHandler {
             : await Promise.all([
                 user.getList(domainId, rdocs.map((rdoc) => rdoc.uid)),
                 canViewProblem
-                    ? problem.getList(domainId, rdocs.map((rdoc) => rdoc.pid), canViewHiddenProblem, this.user.group, false)
+                    ? problem.getList(domainId, rdocs.map((rdoc) => rdoc.pid), canViewHiddenProblem, false)
                     : Object.fromEntries([rdocs.map((rdoc) => [rdoc.pid, { ...problem.default, pid: rdoc.pid }])]),
             ]);
         this.response.body = {
diff --git a/packages/hydrooj/src/handler/training.ts b/packages/hydrooj/src/handler/training.ts
index 35e246d6c..ea840a2a8 100644
--- a/packages/hydrooj/src/handler/training.ts
+++ b/packages/hydrooj/src/handler/training.ts
@@ -98,7 +98,7 @@ class TrainingDetailHandler extends Handler {
         const canViewHidden = this.user.hasPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN) || this.user._id;
         const [owner, pdict] = await Promise.all([
             user.getById(domainId, tdoc.owner),
-            problem.getList(domainId, pids, canViewHidden, this.user.group, true),
+            problem.getList(domainId, pids, canViewHidden, true),
         ]);
         const psdict = await problem.getListStatus(domainId, this.user._id, pids);
         const donePids = new Set<number>();
diff --git a/packages/hydrooj/src/handler/user.ts b/packages/hydrooj/src/handler/user.ts
index ff70d606c..4ca094e6f 100644
--- a/packages/hydrooj/src/handler/user.ts
+++ b/packages/hydrooj/src/handler/user.ts
@@ -344,7 +344,7 @@ class UserDetailHandler extends Handler {
                 pdocs.push(...Object.values(
                     await problem.getList(
                         did, psdocs.map((i) => i.docId), canViewHidden,
-                        this.user.group, false, problem.PROJECTION_LIST, true,
+                        false, problem.PROJECTION_LIST, true,
                     ),
                 ));
             }));
@@ -366,7 +366,7 @@ class UserDetailHandler extends Handler {
             if (this.user.hasPerm(PERM.PERM_VIEW_PROBLEM)) {
                 this.response.body.pdict = await problem.getList(
                     domainId, psdocs.map((i) => i.parentId), canViewHidden,
-                    this.user.group, false, problem.PROJECTION_LIST,
+                    false, problem.PROJECTION_LIST,
                 );
             }
         }
diff --git a/packages/hydrooj/src/interface.ts b/packages/hydrooj/src/interface.ts
index 5e5c548a3..1ea58d51a 100644
--- a/packages/hydrooj/src/interface.ts
+++ b/packages/hydrooj/src/interface.ts
@@ -229,7 +229,6 @@ declare module './model/problem' {
         data: FileInfo[];
         additional_file: FileInfo[];
         hidden?: boolean;
-        assign: string[];
         html?: boolean;
         stats?: any;
         difficulty?: number;
diff --git a/packages/hydrooj/src/model/contest.ts b/packages/hydrooj/src/model/contest.ts
index b44f0ec6b..a14abc0b9 100644
--- a/packages/hydrooj/src/model/contest.ts
+++ b/packages/hydrooj/src/model/contest.ts
@@ -726,7 +726,7 @@ export async function getScoreboard(
     const tdoc = await get(domainId, tid);
     if (!canShowScoreboard.call(this, tdoc)) throw new ContestScoreboardHiddenError(tid);
     const tsdocsCursor = getMultiStatus(domainId, { docId: tid }).sort(RULES[tdoc.rule].statusSort);
-    const pdict = await problem.getList(domainId, tdoc.pids, true, problem.PROJECTION_CONTEST_DETAIL);
+    const pdict = await problem.getList(domainId, tdoc.pids, true, true, problem.PROJECTION_CONTEST_DETAIL);
     const [rows, udict] = await RULES[tdoc.rule].scoreboard(
         isExport, this.translate.bind(this),
         tdoc, pdict, tsdocsCursor,
diff --git a/packages/hydrooj/src/model/problem.ts b/packages/hydrooj/src/model/problem.ts
index 79d71d9da..61a5c6bde 100644
--- a/packages/hydrooj/src/model/problem.ts
+++ b/packages/hydrooj/src/model/problem.ts
@@ -28,7 +28,7 @@ function sortable(source: string) {
 export class ProblemModel {
     static PROJECTION_CONTEST_LIST: Field[] = [
         '_id', 'domainId', 'docType', 'docId', 'pid',
-        'owner', 'title', 'assign',
+        'owner', 'title',
     ];
 
     static PROJECTION_LIST: Field[] = [
@@ -66,7 +66,6 @@ export class ProblemModel {
         additional_file: [],
         stats: {},
         hidden: true,
-        assign: [],
         config: '',
         difficulty: 0,
     };
@@ -88,31 +87,30 @@ export class ProblemModel {
         additional_file: [],
         stats: {},
         hidden: true,
-        assign: [],
         config: '',
         difficulty: 0,
     };
 
     static async add(
         domainId: string, pid: string = '', title: string, content: string, owner: number,
-        tag: string[] = [], hidden = false, assign: string[] = [],
+        tag: string[] = [], hidden = false,
     ) {
         const [doc] = await ProblemModel.getMulti(domainId, {})
             .sort({ docId: -1 }).limit(1).project({ docId: 1 })
             .toArray();
         const result = await ProblemModel.addWithId(
             domainId, (doc?.docId || 0) + 1, pid,
-            title, content, owner, tag, hidden, assign,
+            title, content, owner, tag, hidden,
         );
         return result;
     }
 
     static async addWithId(
         domainId: string, docId: number, pid: string = '', title: string,
-        content: string, owner: number, tag: string[] = [], hidden = false, assign: string[] = [],
+        content: string, owner: number, tag: string[] = [], hidden = false,
     ) {
         const args: Partial<ProblemDoc> = {
-            title, tag, hidden, assign, nSubmit: 0, nAccept: 0, sort: sortable(pid || `P${docId}`),
+            title, tag, hidden, nSubmit: 0, nAccept: 0, sort: sortable(pid || `P${docId}`),
         };
         if (pid) args.pid = pid;
         await bus.parallel('problem/before-add', domainId, content, owner, docId, args);
@@ -298,8 +296,7 @@ export class ProblemModel {
 
     static async getList(
         domainId: string, pids: number[], canViewHidden: number | boolean = false,
-        group: string[] = [], doThrow = true, projection = ProblemModel.PROJECTION_PUBLIC,
-        indexByDocIdOnly = false,
+        doThrow = true, projection = ProblemModel.PROJECTION_PUBLIC, indexByDocIdOnly = false,
     ): Promise<ProblemDict> {
         if (!pids?.length) return [];
         const r: Record<number, ProblemDoc> = {};
@@ -307,9 +304,6 @@ export class ProblemModel {
         const q: any = { docId: { $in: pids } };
         let pdocs = await document.getMulti(domainId, document.TYPE_PROBLEM, q)
             .project(buildProjection(projection)).toArray();
-        if (group.length > 0 && canViewHidden !== true) {
-            pdocs = pdocs.filter((i) => !i.assign?.length || Set.intersection(group, i.assign).size);
-        }
         if (canViewHidden !== true) {
             pdocs = pdocs.filter((i) => i.owner === canViewHidden || i.maintainer?.includes(canViewHidden as any) || !i.hidden);
         }
@@ -383,8 +377,7 @@ export class ProblemModel {
         if (udoc.own(pdoc)) return true;
         if (udoc.hasPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN)) return true;
         if (pdoc.hidden) return false;
-        if (!pdoc.assign.length) return true;
-        return !!Set.intersection(pdoc.assign, udoc.group).size;
+        return true;
     }
 }
 
diff --git a/packages/hydrooj/src/upgrade.ts b/packages/hydrooj/src/upgrade.ts
index a987d555e..606da6874 100644
--- a/packages/hydrooj/src/upgrade.ts
+++ b/packages/hydrooj/src/upgrade.ts
@@ -385,14 +385,7 @@ const scripts: UpgradeScript[] = [
         await db.collection('oplog').deleteMany({ type: 'user.login' });
         return true;
     },
-    async function _57_58() {
-        const _FRESH_INSTALL_IGNORE = 1;
-        await db.collection('document').updateMany(
-            { docType: document.TYPE_PROBLEM, assign: null },
-            { $set: { assign: [] } },
-        );
-        return true;
-    },
+    null,
     async function _58_59() {
         const _FRESH_INSTALL_IGNORE = 1;
         const tasks = await db.collection('task').find({ type: 'schedule', subType: 'contest.problemHide' }).toArray();
diff --git a/packages/ui-default/templates/problem_edit.html b/packages/ui-default/templates/problem_edit.html
index 511f55b09..a1846e4bc 100644
--- a/packages/ui-default/templates/problem_edit.html
+++ b/packages/ui-default/templates/problem_edit.html
@@ -6,12 +6,6 @@
       <div class="section__body">
         <form method="post">
           <div class="row">
-            <div class="medium-7 columns">
-              <label>
-                {{ _('Title') }}
-                <input name="title" placeholder="{{ _('title') }}" value="{{ pdoc['title']|default('') }}" class="textbox"{% if page_name == 'problem_create' %} autofocus{% endif %}>
-              </label>
-            </div>
             <div class="medium-3 columns">
               <label>
                 {{ _('pid') }}
@@ -21,6 +15,12 @@
                 </label>
               </label>
             </div>
+            <div class="medium-7 columns">
+              <label>
+                {{ _('Title') }}
+                <input name="title" placeholder="{{ _('title') }}" value="{{ pdoc['title']|default('') }}" class="textbox"{% if page_name == 'problem_create' %} autofocus{% endif %}>
+              </label>
+            </div>
             <div class="medium-2 columns">
               <label>
                 <br>
@@ -33,20 +33,12 @@
           <div class="row">
           {{ form.form_text({
                row:false,
-               columns:6,
+               columns:9,
                label:'Tags',
                help_text:'Split by \', \'.',
                name:'tag',
                value:pdoc['tag']|default([])|join(', ')
              }) }}
-          {{ form.form_text({
-               row:false,
-               columns:3,
-               label:'Assign',
-               placeholder:_('Group / UID'),
-               name:'assign',
-               value:pdoc.assign|default([])|join(', ')
-             }) }}
           {{ form.form_text({
                row:false,
                columns:3,