diff --git a/ge/graph/manager/graph_var_manager.cc b/ge/graph/manager/graph_var_manager.cc
index 89a4e45b..d0669254 100755
--- a/ge/graph/manager/graph_var_manager.cc
+++ b/ge/graph/manager/graph_var_manager.cc
@@ -20,6 +20,7 @@
 #include "graph/manager/graph_mem_manager.h"
 #include "graph/manager/trans_var_data_utils.h"
 #include "graph/utils/type_utils.h"
+#include "graph/ge_context.h"
 
 using std::map;
 using std::string;
@@ -767,25 +768,52 @@ Status VarManager::GetChangedGraphId(const std::string &var_name, uint32_t &grap
   return var_resource_->GetChangedGraphId(var_name, graph_id);
 }
 
+Status VarManager::GetTotalMemorySize(size_t &total_mem_size) {
+  rtError_t rt_ret = rtSetDevice(GetContext().DeviceId());
+  if (rt_ret != RT_ERROR_NONE) {
+    REPORT_CALL_ERROR("E19999", "Call rtSetDevice failed, device_id:%u, ret:0x%X",
+                      GetContext().DeviceId(), rt_ret);
+    GELOGE(RT_FAILED, "[Call][RtSetDevice] failed, device_id:%u, ret:0x%X", GetContext().DeviceId(), rt_ret);
+    return RT_FAILED;
+  }
+  size_t free_mem = 0;
+  rt_ret = rtMemGetInfoEx(RT_MEMORYINFO_HBM, &free_mem, &total_mem_size);
+  if (rt_ret != RT_ERROR_NONE) {
+    REPORT_CALL_ERROR("E19999", "Call rtMemGetInfo failed, ret:0x%X", rt_ret);
+    GELOGE(RT_FAILED, "[Call][RtMemGetInfo] failed, ret:0x%X", rt_ret);
+    return RT_FAILED;
+  }
+  rt_ret = rtDeviceReset(GetContext().DeviceId());
+  if (rt_ret != RT_ERROR_NONE) {
+    REPORT_CALL_ERROR("E19999", "Call rtDeviceReset failed, device_id:%u, ret:0x%X",
+                      GetContext().DeviceId(), rt_ret);
+    GELOGE(RT_FAILED, "[Call][RtDeviceReset] failed, device_id:%u, ret:0x%X", GetContext().DeviceId(), rt_ret);
+    return RT_FAILED;
+  }
+  return SUCCESS;
+}
+
 Status VarManager::SetMemoryMallocSize(const map<string, string> &options) {
-  auto it = options.find(GRAPH_MEMORY_MAX_SIZE);
-  if (it == options.end()) {
-    graph_mem_max_size_ = kGraphMemoryManagerMallocMaxSize;
-  } else {
-    string graph_memory_manager_malloc_max_size = it->second;
+  size_t total_mem_size = 0;
+  GE_CHK_STATUS_RET_NOLOG(VarManager::GetTotalMemorySize(total_mem_size));
+  GEEVENT("Total memory size is %zu", total_mem_size);
+
+  graph_mem_max_size_ = floor(total_mem_size * kGraphMemoryManagerMallocRatio);
+  var_mem_max_size_ = floor(total_mem_size * kVarMemoryManagerMallocRatio);
+
+  auto it1 = options.find(GRAPH_MEMORY_MAX_SIZE);
+  if (it1 != options.end()) {
+    string graph_memory_manager_malloc_max_size = it1->second;
     ge::Status ret = ParseMemoryMallocSize(graph_memory_manager_malloc_max_size, graph_mem_max_size_);
     if (ret != SUCCESS) {
       GELOGE(ge::GE_GRAPH_OPTIONS_INVALID, "[Call][ParseMemoryMallocSize] failed, session id:%lu.", session_id_);
       return ge::GE_GRAPH_OPTIONS_INVALID;
     }
-    GELOGI("The max size for graph mem is set to %zu", graph_mem_max_size_);
   }
 
-  it = options.find(VARIABLE_MEMORY_MAX_SIZE);
-  if (it == options.end()) {
-    var_mem_max_size_ = kMemoryVarManagerMallocSize;
-  } else {
-    string memory_var_manager_malloc_size = it->second;
+  auto it2 = options.find(VARIABLE_MEMORY_MAX_SIZE);
+  if (it2 != options.end()) {
+    string memory_var_manager_malloc_size = it2->second;
     ge::Status ret = ParseMemoryMallocSize(memory_var_manager_malloc_size, var_mem_max_size_);
     if (ret != SUCCESS) {
       GELOGE(ge::GE_GRAPH_OPTIONS_INVALID, "[Call][ParseMemoryMallocSize] failed, session id:%lu.", session_id_);
@@ -793,6 +821,8 @@ Status VarManager::SetMemoryMallocSize(const map<string, string> &options) {
     }
   }
 
+  GEEVENT("The graph_mem_max_size is %zu and the var_mem_max_size is %zu", graph_mem_max_size_, var_mem_max_size_);
+
   var_mem_logic_base_ = graph_mem_max_size_ + kGraphMemoryBuffer;
   if (var_mem_logic_base_ > kMaxMemorySize) {
     REPORT_INNER_ERROR("E19999", "var_login_base:%zu can not exeed limit:%zu, session_id:%lu, check invalid",
diff --git a/ge/graph/manager/graph_var_manager.h b/ge/graph/manager/graph_var_manager.h
index f2b68e79..a1b45959 100755
--- a/ge/graph/manager/graph_var_manager.h
+++ b/ge/graph/manager/graph_var_manager.h
@@ -43,6 +43,8 @@ const size_t kMaxMemorySize = 256UL * 1024UL * 1024UL * 1024UL;
 const char kEnvGeuseStaticMemory[] = "GE_USE_STATIC_MEMORY";
 const uint64_t kSessionMemAlignSize = 512;
 const size_t kSessionMemAlignUnit = 2;
+const double kGraphMemoryManagerMallocRatio = 26.0 / 32.0;
+const double kVarMemoryManagerMallocRatio = 5.0 / 32.0;
 
 enum MemStatus {
   NORMAL = 0,
@@ -301,6 +303,7 @@ class FMK_FUNC_HOST_VISIBILITY FMK_FUNC_DEV_VISIBILITY VarManager {
   mutable std::recursive_mutex mutex_;
 
   Status ParseMemoryMallocSize(std::string &memory_size, size_t &my_size);
+  Status GetTotalMemorySize(size_t &total_mem_size);
 };
 
 class VarManagerPool {
diff --git a/tests/depends/runtime/src/runtime_stub.cc b/tests/depends/runtime/src/runtime_stub.cc
index 510eb1ad..25d6c2d3 100644
--- a/tests/depends/runtime/src/runtime_stub.cc
+++ b/tests/depends/runtime/src/runtime_stub.cc
@@ -193,6 +193,12 @@ rtError_t rtMemGetInfo(size_t *free, size_t *total) {
   return RT_ERROR_NONE;
 }
 
+rtError_t rtMemGetInfoEx(rtMemInfoType_t memInfoType, size_t *free, size_t *total) {
+  *free = 512UL * 1024UL * 1024UL;
+  *total = 1024UL * 1024UL * 1024UL;
+  return RT_ERROR_NONE;
+}
+
 rtError_t rtMemAllocManaged(void **ptr, uint64_t size, uint32_t flag) { return RT_ERROR_NONE; }
 
 rtError_t rtMemFreeManaged(void *ptr) { return RT_ERROR_NONE; }
diff --git a/tests/ut/ge/CMakeLists.txt b/tests/ut/ge/CMakeLists.txt
index 6dfd3420..49c9161d 100755
--- a/tests/ut/ge/CMakeLists.txt
+++ b/tests/ut/ge/CMakeLists.txt
@@ -690,6 +690,7 @@ set(MULTI_PARTS_TEST_FILES
     "graph/manager/run_graph_unittest.cc"
     "graph/partition/dynamic_shape_partition_unittest.cc"
     "graph/manager/graph_manager_unittest.cc"
+    "graph/manager/graph_var_manager_unittest.cc"
     "graph/optimize/mem_rw_conflict_optimize_unittest.cc"
     "graph/optimize/graph_optimize_unittest.cc"
     "session/omg_omg_unittest.cc"
diff --git a/tests/ut/ge/graph/manager/graph_var_manager_unittest.cc b/tests/ut/ge/graph/manager/graph_var_manager_unittest.cc
new file mode 100644
index 00000000..c20e786d
--- /dev/null
+++ b/tests/ut/ge/graph/manager/graph_var_manager_unittest.cc
@@ -0,0 +1,63 @@
+/**
+ * Copyright 2021 Huawei Technologies Co., Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <gtest/gtest.h>
+#include <memory>
+
+#define protected public
+#define private public
+#include "graph/manager/graph_var_manager.h"
+#include "graph/ge_context.h"
+#undef protected
+#undef private
+
+namespace ge {
+class UtestGraphVarManagerTest : public testing::Test {
+ protected:
+  void SetUp() {}
+  void TearDown() {}
+};
+
+TEST_F(UtestGraphVarManagerTest, test_get_total_memory_size) {
+  size_t total_mem_size = 0;
+  Status ret = VarManager::Instance(0)->GetTotalMemorySize(total_mem_size);
+  EXPECT_EQ(total_mem_size, 1024UL * 1024UL * 1024UL);
+  EXPECT_EQ(ret, SUCCESS);
+}
+
+TEST_F(UtestGraphVarManagerTest, test_set_memory_malloc_size_no_related_option) {
+  const map<string, string> options{};
+  Status ret = VarManager::Instance(0)->SetMemoryMallocSize(options);
+  EXPECT_EQ(VarManager::Instance(0)->graph_mem_max_size_, floor(1024UL * 1024UL * 1024UL * (26.0f / 32.0f)));
+  EXPECT_EQ(VarManager::Instance(0)->var_mem_max_size_, floor(1024UL * 1024UL * 1024UL * (5.0f / 32.0f)));
+  EXPECT_EQ(ret, SUCCESS);
+}
+
+TEST_F(UtestGraphVarManagerTest, test_set_memory_malloc_size_with_user_specify_graph_mem_max_size) {
+  const map<string, string> options{{"ge.graphMemoryMaxSize", "536870912"}};
+  Status ret = VarManager::Instance(0)->SetMemoryMallocSize(options);
+  EXPECT_EQ(VarManager::Instance(0)->graph_mem_max_size_, floor(1024UL * 1024UL * 1024UL / 2));
+  EXPECT_EQ(VarManager::Instance(0)->var_mem_max_size_, floor(1024UL * 1024UL * 1024UL * (5.0f / 32.0f)));
+  EXPECT_EQ(ret, SUCCESS);
+}
+
+TEST_F(UtestGraphVarManagerTest, test_set_memory_malloc_size_with_user_specify_var_mem_max_size) {
+  const map<string, string> options{{"ge.variableMemoryMaxSize", "536870912"}};
+  Status ret = VarManager::Instance(0)->SetMemoryMallocSize(options);
+  EXPECT_EQ(VarManager::Instance(0)->graph_mem_max_size_, floor(1024UL * 1024UL * 1024UL * (26.0f / 32.0f)));
+  EXPECT_EQ(VarManager::Instance(0)->var_mem_max_size_, floor(1024UL * 1024UL * 1024UL / 2));
+  EXPECT_EQ(ret, SUCCESS);
+}
+} // namespace ge