diff --git a/announcement/serializers.py b/announcement/serializers.py
index 1edd1d9..2a2f7b0 100644
--- a/announcement/serializers.py
+++ b/announcement/serializers.py
@@ -18,6 +18,14 @@ class AnnouncementSerializer(serializers.ModelSerializer):
         fields = "__all__"
 
 
+class AnnouncementListSerializer(serializers.ModelSerializer):
+    created_by = UsernameSerializer()
+
+    class Meta:
+        model = Announcement
+        exclude = ['content']
+
+
 class EditAnnouncementSerializer(serializers.Serializer):
     id = serializers.IntegerField()
     title = serializers.CharField(max_length=64)
diff --git a/announcement/views/oj.py b/announcement/views/oj.py
index 1176c36..a745ce7 100644
--- a/announcement/views/oj.py
+++ b/announcement/views/oj.py
@@ -1,10 +1,18 @@
 from utils.api import APIView
 
 from announcement.models import Announcement
-from announcement.serializers import AnnouncementSerializer
+from announcement.serializers import AnnouncementSerializer, AnnouncementListSerializer
 
 
 class AnnouncementAPI(APIView):
     def get(self, request):
+        id = request.GET.get("id")
+        if id:
+            try:
+                announcement = Announcement.objects.get(id=id, visible=True)
+                return self.success(AnnouncementSerializer(announcement).data)
+            except Announcement.DoesNotExist:
+                return self.error("Announcement does not exist")
+
         announcements = Announcement.objects.filter(visible=True)
-        return self.success(self.paginate_data(request, announcements, AnnouncementSerializer))
+        return self.success(self.paginate_data(request, announcements, AnnouncementListSerializer))
diff --git a/problem/serializers.py b/problem/serializers.py
index 099e1f3..3c8ee82 100644
--- a/problem/serializers.py
+++ b/problem/serializers.py
@@ -116,6 +116,11 @@ class ProblemAdminSerializer(BaseProblemSerializer):
         model = Problem
         fields = "__all__"
 
+class ProblemAdminListSerializer(BaseProblemSerializer):
+    class Meta:
+        model = Problem
+        fields = ["_id", "id", "title", "created_by", "visible", "create_time"]
+
 
 class ProblemSerializer(BaseProblemSerializer):
     template = serializers.SerializerMethodField("get_public_template")
@@ -127,16 +132,10 @@ class ProblemSerializer(BaseProblemSerializer):
 
 
 class ProblemListSerializer(BaseProblemSerializer):
-    template = serializers.SerializerMethodField("get_public_template")
-
     class Meta:
         model = Problem
-        exclude = ("test_case_score", "test_case_id", "visible", "is_public",
-                   "spj_code", "spj_version", "spj_compile_ok", "description", 
-                   "input_description", "output_description", "samples", "hint",
-                   "source", "spj", "spj_language", "time_limit", "memory_limit",
-                   "io_mode", "create_time", "languages", "last_update_time",
-                   "total_score", "statistic_info", "share_submission")
+        fields = ["id", "_id", "title", "submission_number", "accepted_number",
+                  "difficulty", "created_by", "tags"]
 
 
 class ProblemSafeSerializer(BaseProblemSerializer):
diff --git a/problem/views/admin.py b/problem/views/admin.py
index 22730c9..d099700 100644
--- a/problem/views/admin.py
+++ b/problem/views/admin.py
@@ -24,8 +24,8 @@ from utils.tasks import delete_files
 from ..models import Problem, ProblemRuleType, ProblemTag
 from ..serializers import (CreateContestProblemSerializer, CompileSPJSerializer,
                            CreateProblemSerializer, EditProblemSerializer, EditContestProblemSerializer,
-                           ProblemAdminSerializer, TestCaseUploadForm, ContestProblemMakePublicSerializer,
-                           AddContestProblemSerializer, ExportProblemSerializer,
+                           ProblemAdminSerializer, ProblemAdminListSerializer, TestCaseUploadForm,
+                           ContestProblemMakePublicSerializer, AddContestProblemSerializer, ExportProblemSerializer,
                            ExportProblemRequestSerializer, UploadProblemForm, ImportProblemSerializer,
                            FPSProblemSerializer)
 from ..utils import TEMPLATE_BASE, build_problem_template
@@ -249,7 +249,7 @@ class ProblemAPI(ProblemBase):
             problems = problems.filter(Q(title__icontains=keyword) | Q(_id__icontains=keyword))
         if not user.can_mgmt_all_problem():
             problems = problems.filter(created_by=user)
-        return self.success(self.paginate_data(request, problems, ProblemAdminSerializer))
+        return self.success(self.paginate_data(request, problems, ProblemAdminListSerializer))
 
     @problem_permission_required
     @validate_serializer(EditProblemSerializer)
@@ -370,7 +370,7 @@ class ContestProblemAPI(ProblemBase):
         keyword = request.GET.get("keyword")
         if keyword:
             problems = problems.filter(title__contains=keyword)
-        return self.success(self.paginate_data(request, problems, ProblemAdminSerializer))
+        return self.success(self.paginate_data(request, problems, ProblemAdminListSerializer))
 
     @validate_serializer(EditContestProblemSerializer)
     def put(self, request):