diff --git a/utils/wxcharts.js b/utils/wxcharts.js
index 6c11715..27b1e81 100644
--- a/utils/wxcharts.js
+++ b/utils/wxcharts.js
@@ -521,7 +521,7 @@ function drawPointShape(points, color, shape, context) {
         points.forEach(function (item, index) {
             if (item !== null) {
                 context.moveTo(item.x + 3.5, item.y);
-                context.arc(item.x, item.y, 4, 0, 2 * Math.PI, false);
+                context.arc(item.x, item.y, 3, 0, 2 * Math.PI, false);
             }
         });
     } else if (shape === 'rect') {