diff --git a/acl/aclbit.go b/acl/aclbit.go
index 1366a50..9646b0a 100644
--- a/acl/aclbit.go
+++ b/acl/aclbit.go
@@ -60,6 +60,15 @@ func (a AclBit) Verify(n NumBit) bool {
 	return false
 }
 
+// verify mask return true or false
+func (a AclBit) VerifyMask(mask AclBit) bool {
+	if (a & mask) > 0 {
+		return true
+	}
+
+	return false
+}
+
 // verify or bit return true or false
 func (a AclBit) VerifyOr(n ...NumBit) bool {
 	for _, n0 := range n {
diff --git a/main.go b/main.go
index a38b3e5..51e5275 100644
--- a/main.go
+++ b/main.go
@@ -50,4 +50,6 @@ func main() {
 	}
 	fmt.Println(ret)
 	fmt.Println(acl.AllBit)
+
+	fmt.Println(16 & 32)
 }