diff --git a/README.md b/README.md
index 90be2a83..b9f57a21 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,16 @@
 
 The universal proxy platform.
 
+## Repository Notice
+
+This repository is a customized fork based on the upstream [SagerNet/sing-box](https://github.com/SagerNet/sing-box) project.
+
+- Upstream project: `sing-box`
+- Upstream documentation: https://sing-box.sagernet.org
+- This repository may contain local modifications for Xboard integration, deployment scripts, and protocol handling behavior
+
+If you are looking for the official project, feature baseline, or upstream release notes, please refer to the upstream `sing-box` repository first.
+
 [![Packaging status](https://repology.org/badge/vertical-allrepos/sing-box.svg)](https://repology.org/project/sing-box/versions)
 
 ## Documentation
@@ -36,4 +46,4 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 In addition, no derivative work may use the name or imply association
 with this application without prior consent.
-```
\ No newline at end of file
+```