diff --git a/config/config2.example.yaml b/config/config2.example.yaml
index fd4409f97..6d6e32383 100644
--- a/config/config2.example.yaml
+++ b/config/config2.example.yaml
@@ -87,6 +87,7 @@ role_zero:
   enable_longterm_memory: false # Whether to use long-term memory. Default is `false`.
   longterm_memory_persist_path: .role_memory_data # The directory to save data.
   memory_k: 200 # The capacity of short-term memory.
+  similarity_top_k: 5 # The number of long-term memories to retrieve.
 
 azure_tts_subscription_key: "YOUR_SUBSCRIPTION_KEY"
 azure_tts_region: "eastus"
diff --git a/metagpt/configs/role_zero_config.py b/metagpt/configs/role_zero_config.py
index 21d50a3ac..17cb295ab 100644
--- a/metagpt/configs/role_zero_config.py
+++ b/metagpt/configs/role_zero_config.py
@@ -7,3 +7,4 @@ class RoleZeroConfig(YamlModel):
     enable_longterm_memory: bool = Field(default=False, description="Whether to use long-term memory.")
     longterm_memory_persist_path: str = Field(default=".role_memory_data", description="The directory to save data.")
     memory_k: int = Field(default=200, description="The capacity of short-term memory.")
+    similarity_top_k: int = Field(default=5, description="The number of long-term memories to retrieve.")
diff --git a/metagpt/memory/role_zero_memory.py b/metagpt/memory/role_zero_memory.py
index 5c7fb94a2..87973ba3b 100644
--- a/metagpt/memory/role_zero_memory.py
+++ b/metagpt/memory/role_zero_memory.py
@@ -31,6 +31,7 @@ class RoleZeroLongTermMemory(Memory):
     persist_path: str = Field(default=".role_memory_data", description="The directory to save data.")
     collection_name: str = Field(default="role_zero", description="The name of the collection, such as the role name.")
     memory_k: int = Field(default=200, description="The capacity of short-term memory.")
+    similarity_top_k: int = Field(default=5, description="The number of long-term memories to retrieve.")
 
     _rag_engine: Any = None
 
@@ -54,7 +55,11 @@ class RoleZeroLongTermMemory(Memory):
             raise ImportError("To use the RoleZeroMemory, you need to install the rag module.")
 
         retriever_configs = [
-            ChromaRetrieverConfig(persist_path=self.persist_path, collection_name=self.collection_name)
+            ChromaRetrieverConfig(
+                persist_path=self.persist_path,
+                collection_name=self.collection_name,
+                similarity_top_k=self.similarity_top_k,
+            )
         ]
         ranker_configs = []
 
diff --git a/metagpt/roles/di/role_zero.py b/metagpt/roles/di/role_zero.py
index b202fd3cc..8c636ad38 100644
--- a/metagpt/roles/di/role_zero.py
+++ b/metagpt/roles/di/role_zero.py
@@ -185,6 +185,7 @@ class RoleZero(Role):
                 persist_path=self.config.role_zero.longterm_memory_persist_path,
                 collection_name=self.name.replace(" ", ""),
                 memory_k=self.config.role_zero.memory_k,
+                similarity_top_k=self.config.role_zero.similarity_top_k,
             )
             logger.info(f"Long-term memory set for role '{self.name}'")