diff --git a/apps/library/serializers_admin.py b/apps/library/serializers_admin.py
index face95f..d99337f 100644
--- a/apps/library/serializers_admin.py
+++ b/apps/library/serializers_admin.py
@@ -145,6 +145,41 @@ class AdminBookListSerializer(serializers.ModelSerializer):
         ]
         read_only_fields = ["id", "view_count", "download_count", "created_at", "updated_at"]
 
+import json
+
+class FlexibleJSONListField(serializers.Field):
+    def to_internal_value(self, data):
+        if data is None or data == "":
+            return []
+        if isinstance(data, list):
+            return data
+        if isinstance(data, str):
+            data = data.strip()
+            if not data:
+                return []
+            try:
+                parsed = json.loads(data)
+                if isinstance(parsed, list):
+                    return parsed
+                return [parsed]
+            except (ValueError, json.JSONDecodeError):
+                return [item.strip() for item in data.split(",") if item.strip()]
+        return []
+
+    def to_representation(self, value):
+        if isinstance(value, list):
+            return value
+        if isinstance(value, str):
+            try:
+                parsed = json.loads(value)
+                if isinstance(parsed, list):
+                    return parsed
+            except Exception:
+                pass
+            return [value] if value else []
+        return []
+
+
 from dj_language.models import Language
 class AdminBookDetailSerializer(serializers.ModelSerializer):
     thumbnail = AbsoluteImageField(required=False, allow_null=True)
@@ -157,6 +192,8 @@ class AdminBookDetailSerializer(serializers.ModelSerializer):
     collections_detail = AdminLibraryCollectionSerializer(source="collections", many=True, read_only=True)
     remove_thumbnail = serializers.BooleanField(write_only=True, required=False, default=False)
     remove_book_file = serializers.BooleanField(write_only=True, required=False, default=False)
+    main_themes = FlexibleJSONListField(required=False, default=list)
+    notable_works = FlexibleJSONListField(required=False, default=list)
     language = serializers.SlugRelatedField(
         slug_field='code', 
         queryset=Language.objects.all(),
@@ -205,22 +242,6 @@ class AdminBookDetailSerializer(serializers.ModelSerializer):
         ]
         read_only_fields = ["id", "view_count", "download_count", "bookmark_count", "created_at", "updated_at"]
 
-    def to_internal_value(self, data):
-        import json
-        if hasattr(data, "copy"):
-            mutable_data = data.copy()
-        else:
-            mutable_data = dict(data)
-
-        for json_field in ["main_themes", "notable_works"]:
-            val = mutable_data.get(json_field)
-            if isinstance(val, str):
-                try:
-                    mutable_data[json_field] = json.loads(val)
-                except ValueError:
-                    pass
-        return super().to_internal_value(mutable_data)
-
     def get_bookmark_count(self, obj):
         from apps.bookmark.models.bookmark import Bookmark
         return Bookmark.objects.filter(service=Bookmark.ServiceChoices.LIBRARY, content_id=obj.id, status=True).count()