diff --git a/core/conf/config_test.go b/core/conf/config_test.go
index 356db8bf..8f114e4a 100644
--- a/core/conf/config_test.go
+++ b/core/conf/config_test.go
@@ -6,9 +6,21 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/tal-tech/go-zero/core/fs"
 	"github.com/tal-tech/go-zero/core/hash"
 )
 
+func TestLoadConfig_notExists(t *testing.T) {
+	assert.NotNil(t, LoadConfig("not_a_file", nil))
+}
+
+func TestLoadConfig_notRecogFile(t *testing.T) {
+	filename, err := fs.TempFilenameWithText("hello")
+	assert.Nil(t, err)
+	defer os.Remove(filename)
+	assert.NotNil(t, LoadConfig(filename, nil))
+}
+
 func TestConfigJson(t *testing.T) {
 	tests := []string{
 		".json",
diff --git a/core/conf/properties_test.go b/core/conf/properties_test.go
index 9cb4e545..a83a8447 100644
--- a/core/conf/properties_test.go
+++ b/core/conf/properties_test.go
@@ -24,6 +24,20 @@ func TestProperties(t *testing.T) {
 	assert.Equal(t, "test", props.GetString("app.name"))
 	assert.Equal(t, "app", props.GetString("app.program"))
 	assert.Equal(t, 5, props.GetInt("app.threads"))
+
+	val := props.ToString()
+	assert.Contains(t, val, "app.name")
+	assert.Contains(t, val, "app.program")
+	assert.Contains(t, val, "app.threads")
+}
+
+func TestLoadProperties_badContent(t *testing.T) {
+	filename, err := fs.TempFilenameWithText("hello")
+	assert.Nil(t, err)
+	defer os.Remove(filename)
+	_, err = LoadProperties(filename)
+	assert.NotNil(t, err)
+	assert.True(t, len(err.Error()) > 0)
 }
 
 func TestSetString(t *testing.T) {