diff --git a/apps/setting/models_provider/impl/base_chat_open_ai.py b/apps/setting/models_provider/impl/base_chat_open_ai.py
index 38b6b20fc..0989517a7 100644
--- a/apps/setting/models_provider/impl/base_chat_open_ai.py
+++ b/apps/setting/models_provider/impl/base_chat_open_ai.py
@@ -104,7 +104,7 @@ class BaseChatOpenAI(ChatOpenAI):
                 if generation_chunk.message.usage_metadata is not None:
                     self.usage_metadata = generation_chunk.message.usage_metadata
                 # custom code
-                if 'reasoning_content' in chunk['choices'][0]['delta']:
+                if len(chunk['choices']) > 0 and 'reasoning_content' in chunk['choices'][0]['delta']:
                     generation_chunk.message.additional_kwargs["reasoning_content"] = chunk['choices'][0]['delta'][
                         'reasoning_content']