diff --git a/mindspore/ccsrc/frontend/operator/composite/do_signature.cc b/mindspore/ccsrc/frontend/operator/composite/do_signature.cc
index 133fb4732c2..c980da5c66a 100644
--- a/mindspore/ccsrc/frontend/operator/composite/do_signature.cc
+++ b/mindspore/ccsrc/frontend/operator/composite/do_signature.cc
@@ -247,15 +247,25 @@ void DoAutoCast(const std::string &func_name, const std::vector<Signature> &sign
   }
 }
 
-void CheckSigSize(const size_t &sig_size, const bool &has_var, const AbstractBasePtrList &args_spec_list,
-                  const std::string &func_name) {
+void CheckSigSize(const ValuePtr &function, const size_t &sig_size, const bool &has_var,
+                  const AbstractBasePtrList &args_spec_list, const std::string &func_name) {
   if (sig_size > 0) {
     if (has_var) {
       if (sig_size - 1 > args_spec_list.size()) {
         MS_LOG(EXCEPTION) << "Function " << func_name
                           << "'s input length less than PositionalKeyword Signature length.";
       }
-    } else if (args_spec_list.size() > sig_size) {
+      return;
+    }
+    // Consider the case where there are monads in primitive's args_spec_list.
+    size_t args_size = args_spec_list.size();
+    if (function->isa<Primitive>()) {
+      auto prim = function->cast<PrimitivePyPtr>();
+      if (prim->HasAttr(GRAPH_FLAG_SIDE_EFFECT_MEM) || prim->HasAttr(GRAPH_FLAG_SIDE_EFFECT_IO)) {
+        args_size -= GetAbstractMonadNum(args_spec_list);
+      }
+    }
+    if (args_size > sig_size) {
       MS_LOG(EXCEPTION) << "Function " << func_name << "'s input length is not equal to Signature length.";
     }
   }
@@ -279,7 +289,7 @@ AnfNodePtr BuildNewCNode(const FuncGraphPtr &func_graph, const std::string &func
   auto &signature = GetSignature(function);
   std::size_t sig_size = signature.size();
   auto has_var = (sig_size > 0 && signature[sig_size - 1].kind == SignatureEnumKind::kKindVarPositional);
-  CheckSigSize(sig_size, has_var, args_spec_list, func_name);
+  CheckSigSize(function, sig_size, has_var, args_spec_list, func_name);
   std::vector<AnfNodePtr> op_inputs;
   std::set<size_t> write_indices;
   std::vector<TypePtr> input_types;
diff --git a/mindspore/python/mindspore/ops/operations/other_ops.py b/mindspore/python/mindspore/ops/operations/other_ops.py
index 4503b0d23dc..00c77d91627 100644
--- a/mindspore/python/mindspore/ops/operations/other_ops.py
+++ b/mindspore/python/mindspore/ops/operations/other_ops.py
@@ -15,7 +15,6 @@
 
 """Other operators."""
 import functools
-import mindspore.common._monad as monad
 from mindspore import log as logger
 from .. import signature as sig
 from ..._checkparam import Validator as validator, Rel
@@ -59,8 +58,7 @@ class Assign(Primitive):
     """
     __mindspore_signature__ = (
         sig.make_sig('variable', sig.sig_rw.RW_WRITE, dtype=sig.sig_dtype.T),
-        sig.make_sig('value', dtype=sig.sig_dtype.T),
-        sig.make_sig('u', default=monad.U, dtype=sig.sig_dtype.T1)
+        sig.make_sig('value', dtype=sig.sig_dtype.T)
     )
 
     @prim_attr_register