先下载一个画各种图形的JS库
http://pan.baidu.com/s/1sjyTqaT
然后使用
var point=new GLatLng(lat,lng);
map.addOverlay(GPolygon.Circle(point, radius, "red", 3, 1, "red", 0.3));
map.addOverlay(GPolyline.Circle(glatlng, radius, "red", 3, 1, "red", 0.3));
原文：http://www.cnblogs.com/bens/p/4348279.html