diff --git a/test/str_test.go b/test/str_test.go
new file mode 100644
index 0000000..02a7d67
--- /dev/null
+++ b/test/str_test.go
@@ -0,0 +1,14 @@
+package test
+
+import (
+	"fmt"
+	"git.sre.ink/go/gtool"
+	"testing"
+)
+
+func TestStr(tt *testing.T) {
+	fmt.Println(gtool.Str.HexEncode("hello world!"))
+	//68656c6c6f20776f726c6421
+	fmt.Println(gtool.Str.HexDecode("68656c6c6f20776f726c6421"))
+	//hello world! <nil>
+}