diff --git a/lightrag/operate.py b/lightrag/operate.py
index 66e4533c..cf096993 100644
--- a/lightrag/operate.py
+++ b/lightrag/operate.py
@@ -1025,6 +1025,10 @@ async def _build_query_context(
             [hl_relations_context, ll_relations_context],
             [hl_text_units_context, ll_text_units_context],
         )
+    # not necessary to use LLM to generate a response
+    if not entities_context.strip() and not relations_context.strip():
+        return None
+        
     return f"""
 -----Entities-----
 ```csv