腾讯:http://ip.qq.com/cgi-bin/searchip?searchip1=121.236.225.37 现在只能通过解析页面内容到取得

新浪:http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=json&ip=123.124.2.85

网易: http://www.youdao.com/smartresult-xml/search.s?type=ip&q=123.124.2.85

ip地址在各个国家的分配情况表: http://ftp.apnic.net/apnic/stats/apnic/delegated-apnic-latest http://www.countryipblocks.net/country-blocks/ip-range-format/