With the development of active proxy, the functions of a proxy have been enhanced beyond simply storing Web contents. Web prefetching activity in proxy is such an example to reduce client-perceived latency. In this paper, we propose a coordinated proxy-server prefetching technique that adaptively utilizes the access information and coordinates prefetching activities at both proxy and Web servers. In our design, the access information stored in proxies will be the main source serving data prefetching for groups of clients sharing common surfing interests. The access information in the Web server will be used to serve data prefetching only for data objects that are not qualified for proxy-based prefetching. Conducting trace-driven simulations, we show that both hit ratios and byte hit ratios contributed from coordinated proxy-server prefetching are 30-75% higher than other prefetching schemes, and they are comparable to the ratios from a proxyless server-based prefetching that is able to observe every access to the server.