Abstract: The size of WWW has become huge. The distributed, dynamical and evolutionary characteristics of WWW provide good evidences to study complex systems. Web user’s surfing behaviors are studied based on a multi-agent system. Web user is viewed as information agent surfing in virtual web information space. The results indicate that surfing pattern of web user depends on particular distribution of user interest, and also there exists a web topology which could achieve optimal effect between information that user has got and user surfing steps.