diff --git a/README.md b/README.md
index c9a35a3..6eaf353 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ world-geo-json-zh
 
 简体中文 Geo JSON 世界地图，带有国家（地区）的 ISO 3166 代码、中文简称与全称。含中国南海海域十段线。
 
-A simplified Chinese world map in GeoJSON format, including ISO 3166 codes, Chinese short names, and full names of countries (regions).
+A simplified Chinese world map in GeoJSON format, including ISO 3166 codes, Chinese short names, and full names of countries (regions). Contains China's Ten-Dash Line.
 
 🌏 [Data](https://github.com/Surbowl/world-geo-json-zh/blob/main/world.zh.json)