在 http://ip.qq.com/ 的网站中有QQ自己的JS省市区三级联动
QQ是使用引用外部JS来实现三级联动的。JS如下：http://ip.qq.com/js/geo.js
<!DOCTYPE html> <html> <head> <title>QQ JS省市区三级联动</title> <!-- 直接使用QQ的省市区数据 --> <!-- <script type="text/javascript" src="http://ip.qq.com/js/geo.js"></script> --> <script type="text/javascript" src="geo.js"></script> </head> <body onload="setup();preselect('陕西省');promptinfo();"> <form> <select class="select" name="province" id="s1"> <option></option> </select> <select class="select" name="city" id="s2"> <option></option> </select> <select class="select" name="town" id="s3"> <option></option> </select> <input id="address" name="address" type="hidden" value="" /> <input onclick="alert(document.getElementById('address').value); return false;" type="submit" value="提交" /> </form> <script> //这个函数是必须的，因为在geo.js里每次更改地址时会调用此函数 function promptinfo() { var address = document.getElementById('address'); var s1 = document.getElementById('s1'); var s2 = document.getElementById('s2'); var s3 = document.getElementById('s3'); address.value = s1.value + s2.value + s3.value; } </script> </body> </html>