diff --git a/imperative/python/megengine/__init__.py b/imperative/python/megengine/__init__.py
index a980024a615620d74c3e686d56fc475dccd41a2f..cee58727ef11296eeb4920c03a81140f6f168902 100644
--- a/imperative/python/megengine/__init__.py
+++ b/imperative/python/megengine/__init__.py
@@ -76,7 +76,7 @@ if sys.platform == "win32":
     kernel32.SetErrorMode(old_error_mode)
 
 from .core._imperative_rt.core2 import close as _close
-from .core._imperative_rt.core2 import full_sync as sync
+from .core._imperative_rt.core2 import full_sync as _full_sync
 from .core._imperative_rt.core2 import sync as _sync
 from .core._imperative_rt.utils import _set_fork_exec_path_for_timed_func
 from .config import *
diff --git a/imperative/python/megengine/device.py b/imperative/python/megengine/device.py
index e5f92b993b4713891c09cfe6f06db65bc7689b80..9ba1c4d640f87ff76be2263048860dfd5ee4a018 100644
--- a/imperative/python/megengine/device.py
+++ b/imperative/python/megengine/device.py
@@ -165,7 +165,7 @@ def get_cuda_compute_capability(device: int, device_type=DeviceType.CUDA) -> int
 def get_allocated_memory(device: Optional[str] = None):
     r"""Returns the current memory occupied by tensors on the computing device in bytes.
 
-    Due to the asynchronous execution of MegEngine, please call megengine.sync
+    Due to the asynchronous execution of MegEngine, please call megengine._full_sync
     before calling this function in order to get accurate value.
     """
     if device is None:
@@ -176,7 +176,7 @@ def get_allocated_memory(device: Optional[str] = None):
 def get_reserved_memory(device: Optional[str] = None):
     r"""Returns the current memory managed by the caching allocator on the computing device in bytes.
 
-    Due to the asynchronous execution of MegEngine, please call megengine.sync
+    Due to the asynchronous execution of MegEngine, please call megengine._full_sync
     before calling this function in order to get accurate value.
     """
     if device is None:
@@ -187,7 +187,7 @@ def get_reserved_memory(device: Optional[str] = None):
 def get_max_reserved_memory(device: Optional[str] = None):
     r"""Returns the maximum memory managed by the caching allocator on the computing device in bytes.
 
-    Due to the asynchronous execution of MegEngine, please call megengine.sync
+    Due to the asynchronous execution of MegEngine, please call megengine._full_sync
     before calling this function in order to get accurate value.
     """
     if device is None:
@@ -198,7 +198,7 @@ def get_max_reserved_memory(device: Optional[str] = None):
 def get_max_allocated_memory(device: Optional[str] = None):
     r"""Returns the maximum memory occupied by tensors on the computing device in bytes.
 
-    Due to the asynchronous execution of MegEngine, please call megengine.sync
+    Due to the asynchronous execution of MegEngine, please call megengine._full_sync
     before calling this function in order to get accurate value.
     """
     if device is None:
@@ -209,7 +209,7 @@ def get_max_allocated_memory(device: Optional[str] = None):
 def reset_max_memory_stats(device: Optional[str] = None):
     r"""Resets the maximum stats on the computing device.
 
-    Due to the asynchronous execution of MegEngine, please call megengine.sync
+    Due to the asynchronous execution of MegEngine, please call megengine._full_sync
     before calling this function in order to properly reset memory stats.
     """
     if device is None:
@@ -255,7 +255,7 @@ def coalesce_free_memory():
     small pieces may not be returned.
     
     because of the async processing of megengine, the effect of this func may not be reflected 
-    immediately. if you want to see the effect immediately, you can call megengine.sync after
+    immediately. if you want to see the effect immediately, you can call megengine._full_sync after
     this func was called
 
     .. note::
diff --git a/imperative/python/megengine/tools/benchmark_op.py b/imperative/python/megengine/tools/benchmark_op.py
index e178dddfde50ed0af41bfeca66ff6f7753108c39..19bf0ff9e3d0df8a418cd0b3beaa09fff8be8daf 100644
--- a/imperative/python/megengine/tools/benchmark_op.py
+++ b/imperative/python/megengine/tools/benchmark_op.py
@@ -400,14 +400,14 @@ test_cases = [
 
 def perf_func(func, inps, reps, unpack_inps, is_mge):
     if is_mge:
-        mge.sync()
+        mge._full_sync()
         tik = time.time()
         for _ in range(reps):
             if unpack_inps:
                 out = func(*inps)
             else:
                 out = func(inps)
-        mge.sync()
+        mge._full_sync()
     else:
         torch.cuda.synchronize()
         with torch.no_grad():