diff --git a/os/gcfg/gcfg.go b/os/gcfg/gcfg.go
index 7a40edac7..0f1f8babb 100644
--- a/os/gcfg/gcfg.go
+++ b/os/gcfg/gcfg.go
@@ -26,8 +26,8 @@ import (
 )
 
 const (
-	// DEFAULT_CONFIG_FILE is the default configuration file name.
-	DEFAULT_CONFIG_FILE = "config.toml"
+	DEFAULT_CONFIG_FILE = "config.toml" // The default configuration file name.
+	gCMDENV_KEY         = "gf.gcfg"     // Configuration key for command argument or environment.
 )
 
 // Configuration struct.
@@ -55,7 +55,7 @@ func New(file ...string) *Config {
 		jsons: gmap.NewStrAnyMap(true),
 	}
 	// Customized dir path from env/cmd.
-	if envPath := cmdenv.Get("gf.gcfg.path").String(); envPath != "" {
+	if envPath := cmdenv.Get(fmt.Sprintf("%s.path", gCMDENV_KEY)).String(); envPath != "" {
 		if gfile.Exists(envPath) {
 			_ = c.SetPath(envPath)
 		} else {
diff --git a/os/gtimer/gtimer.go b/os/gtimer/gtimer.go
index 748bd5239..c938b946f 100644
--- a/os/gtimer/gtimer.go
+++ b/os/gtimer/gtimer.go
@@ -20,6 +20,7 @@
 package gtimer
 
 import (
+	"fmt"
 	"math"
 	"time"
 
@@ -36,12 +37,13 @@ const (
 	gDEFAULT_SLOT_NUMBER    = 10            // Default slot number.
 	gDEFAULT_WHEEL_INTERVAL = 50            // Default wheel interval.
 	gDEFAULT_WHEEL_LEVEL    = 6             // Default wheel level.
+	gCMDENV_KEY             = "gf.gtimer"   // Configuration key for command argument or environment.
 )
 
 var (
-	defaultSlots    = cmdenv.Get("gf.gtimer.slots", gDEFAULT_SLOT_NUMBER).Int()
-	defaultLevel    = cmdenv.Get("gf.gtimer.level", gDEFAULT_WHEEL_LEVEL).Int()
-	defaultInterval = cmdenv.Get("gf.gtimer.interval", gDEFAULT_WHEEL_INTERVAL).Duration() * time.Millisecond
+	defaultSlots    = cmdenv.Get(fmt.Sprintf("%s.slots", gCMDENV_KEY), gDEFAULT_SLOT_NUMBER).Int()
+	defaultLevel    = cmdenv.Get(fmt.Sprintf("%s.level", gCMDENV_KEY), gDEFAULT_WHEEL_LEVEL).Int()
+	defaultInterval = cmdenv.Get(fmt.Sprintf("%s.interval", gCMDENV_KEY), gDEFAULT_WHEEL_INTERVAL).Duration() * time.Millisecond
 	defaultTimer    = New(defaultSlots, defaultInterval, defaultLevel)
 )
 
diff --git a/util/gmode/gmode.go b/util/gmode/gmode.go
index ee8c104ff..5a74d0b69 100644
--- a/util/gmode/gmode.go
+++ b/util/gmode/gmode.go
@@ -9,14 +9,19 @@
 // It uses string to mark the mode instead of integer, which is convenient for configuration.
 package gmode
 
-import "github.com/gogf/gf/os/gfile"
+import (
+	"github.com/gogf/gf/debug/gdebug"
+	"github.com/gogf/gf/internal/cmdenv"
+	"github.com/gogf/gf/os/gfile"
+)
 
 const (
-	NOT_SET = "not-set"
-	DEVELOP = "develop"
-	TESTING = "testing"
-	STAGING = "staging"
-	PRODUCT = "product"
+	NOT_SET     = "not-set"
+	DEVELOP     = "develop"
+	TESTING     = "testing"
+	STAGING     = "staging"
+	PRODUCT     = "product"
+	gCMDENV_KEY = "gf.gmode"
 )
 
 var (
@@ -52,10 +57,16 @@ func SetProduct() {
 func Mode() string {
 	// If current mode is not set, do this auto check.
 	if currentMode == NOT_SET {
-		if gfile.MainPkgPath() != "" {
-			return DEVELOP
+		if v := cmdenv.Get(gCMDENV_KEY).String(); v != "" {
+			// Mode configured from command argument of environment.
+			currentMode = v
 		} else {
-			return PRODUCT
+			// If there are source codes found, it's in develop mode, or else in product mode.
+			if gfile.Exists(gdebug.CallerFilePath()) {
+				currentMode = DEVELOP
+			} else {
+				currentMode = PRODUCT
+			}
 		}
 	}
 	return currentMode
diff --git a/util/gmode/gmode_test.go b/util/gmode/gmode_test.go
new file mode 100644
index 000000000..0d0cf20a8
--- /dev/null
+++ b/util/gmode/gmode_test.go
@@ -0,0 +1,61 @@
+// Copyright 2020 gf Author(https://github.com/gogf/gf). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+// go test *.go -bench=".*"
+
+package gmode_test
+
+import (
+	"github.com/gogf/gf/util/gmode"
+	"testing"
+
+	"github.com/gogf/gf/test/gtest"
+)
+
+func Test_AutoCheckSourceCodes(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		t.Assert(gmode.IsDevelop(), true)
+	})
+}
+
+func Test_Set(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		oldMode := gmode.Mode()
+		defer gmode.Set(oldMode)
+		gmode.SetDevelop()
+		t.Assert(gmode.IsDevelop(), true)
+		t.Assert(gmode.IsTesting(), false)
+		t.Assert(gmode.IsStaging(), false)
+		t.Assert(gmode.IsProduct(), false)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		oldMode := gmode.Mode()
+		defer gmode.Set(oldMode)
+		gmode.SetTesting()
+		t.Assert(gmode.IsDevelop(), false)
+		t.Assert(gmode.IsTesting(), true)
+		t.Assert(gmode.IsStaging(), false)
+		t.Assert(gmode.IsProduct(), false)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		oldMode := gmode.Mode()
+		defer gmode.Set(oldMode)
+		gmode.SetStaging()
+		t.Assert(gmode.IsDevelop(), false)
+		t.Assert(gmode.IsTesting(), false)
+		t.Assert(gmode.IsStaging(), true)
+		t.Assert(gmode.IsProduct(), false)
+	})
+	gtest.C(t, func(t *gtest.T) {
+		oldMode := gmode.Mode()
+		defer gmode.Set(oldMode)
+		gmode.SetProduct()
+		t.Assert(gmode.IsDevelop(), false)
+		t.Assert(gmode.IsTesting(), false)
+		t.Assert(gmode.IsStaging(), false)
+		t.Assert(gmode.IsProduct(), true)
+	})
+}