Web Cluster is an effective mechanism used in Web site construction to deal with the system capacity prob-lem. Researchers proposed several strategies or algorithms, which improve the performance and scalability of the Webcluster system. In this paper, a content-based load distribution algorithm is proposed. It takes the processing ability ofback-end severs and the request load weight into account, and ensure the request locality. The emulation results illus-trate that this algorithm performs better in different kinds of Web site, comparing with other relative algorithms.