diff --git a/backend/leetcode/__init__.py b/backend/leetcode/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/backend/leetcode/admin.py b/backend/leetcode/admin.py
new file mode 100644
index 0000000..d1fcd78
--- /dev/null
+++ b/backend/leetcode/admin.py
@@ -0,0 +1,7 @@
+from django.contrib import admin
+from .models import LeetCodeRecord
+@admin.register(LeetCodeRecord)
+class LeetCodeRecordAdmin(admin.ModelAdmin):
+    list_display = ("user","problem_id","title","difficulty","status","solved_at","updated_at")
+    search_fields = ("title","problem_id","user__username")
+    list_filter = ("difficulty","status")
\ No newline at end of file
diff --git a/backend/leetcode/models.py b/backend/leetcode/models.py
new file mode 100644
index 0000000..07395d4
--- /dev/null
+++ b/backend/leetcode/models.py
@@ -0,0 +1,21 @@
+from django.conf import settings
+from django.db import models
+
+class LeetCodeRecord(models.Model):
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="leetcode_records")
+    problem_id = models.CharField(max_length=64)          # 如 1, 2, 3 或 slug
+    title = models.CharField(max_length=255)
+    url = models.URLField(blank=True)
+    difficulty = models.CharField(max_length=16, choices=[("easy","easy"),("medium","medium"),("hard","hard")])
+    status = models.CharField(max_length=16, choices=[("solved","solved"),("attempted","attempted")], default="solved")
+    language = models.CharField(max_length=64, blank=True) # Python/Java/C++ 等
+    tags = models.JSONField(default=list, blank=True)      # sqlite 可用 JSONField
+    time_spent_min = models.PositiveIntegerField(default=0)
+    notes = models.TextField(blank=True)
+    solved_at = models.DateTimeField(null=True, blank=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        unique_together = ("user", "problem_id")
+        ordering = ["-solved_at", "-updated_at"]
diff --git a/backend/leetcode/urls.py b/backend/leetcode/urls.py
new file mode 100644
index 0000000..4dcb11c
--- /dev/null
+++ b/backend/leetcode/urls.py
@@ -0,0 +1,19 @@
+from rest_framework import viewsets, permissions, filters
+from django_filters.rest_framework import DjangoFilterBackend
+from .models import LeetCodeRecord
+from .serializers import LeetCodeRecordSerializer
+
+class LeetCodeRecordViewSet(viewsets.ModelViewSet):
+    permission_classes = [permissions.IsAuthenticated]
+    serializer_class = LeetCodeRecordSerializer
+
+    filter_backends = [DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter]
+    filterset_fields = ["difficulty","status"]
+    search_fields = ["title","problem_id","tags"]
+    ordering_fields = ["solved_at","updated_at","time_spent_min"]
+
+    def get_queryset(self):
+        return LeetCodeRecord.objects.filter(user=self.request.user)
+
+    def perform_create(self, serializer):
+        serializer.save(user=self.request.user)
diff --git a/backend/leetcode/view.py b/backend/leetcode/view.py
new file mode 100644
index 0000000..4dcb11c
--- /dev/null
+++ b/backend/leetcode/view.py
@@ -0,0 +1,19 @@
+from rest_framework import viewsets, permissions, filters
+from django_filters.rest_framework import DjangoFilterBackend
+from .models import LeetCodeRecord
+from .serializers import LeetCodeRecordSerializer
+
+class LeetCodeRecordViewSet(viewsets.ModelViewSet):
+    permission_classes = [permissions.IsAuthenticated]
+    serializer_class = LeetCodeRecordSerializer
+
+    filter_backends = [DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter]
+    filterset_fields = ["difficulty","status"]
+    search_fields = ["title","problem_id","tags"]
+    ordering_fields = ["solved_at","updated_at","time_spent_min"]
+
+    def get_queryset(self):
+        return LeetCodeRecord.objects.filter(user=self.request.user)
+
+    def perform_create(self, serializer):
+        serializer.save(user=self.request.user)
diff --git a/backend/project/settings.py b/backend/project/settings.py
index f2b3e94..e83ca4b 100644
--- a/backend/project/settings.py
+++ b/backend/project/settings.py
@@ -49,14 +49,25 @@
 ]
 
 REST_FRAMEWORK = {
+
     "DEFAULT_AUTHENTICATION_CLASSES": [
         "rest_framework.authentication.TokenAuthentication",
+        "rest_framework.authentication.SessionAuthentication",
     ],
+
     "DEFAULT_PERMISSION_CLASSES": [
         "rest_framework.permissions.IsAuthenticated",
     ],
-}
 
+    "DEFAULT_FILTER_BACKENDS": [
+        "django_filters.rest_framework.DjangoFilterBackend",
+        "rest_framework.filters.SearchFilter",
+        "rest_framework.filters.OrderingFilter",
+    ],
+
+    "DEFAULT_PAGINATION_CLASS": "rest_framework.pagination.PageNumberPagination",
+    "PAGE_SIZE": 20,
+}
 ALLOWED_HOSTS = ["127.0.0.1", "localhost"]
 
 MEDIA_URL = "/media/"