Abstract: Load balancing is the research focus of P2P system.Aiming at the shortage of existed load balancing algorithm, an active load balancing agent based on mobile is proposed.The algorithm collects load information using mobile agent, generates load migration decisions, reducing the system's communication costs, and avoid single point failures and the "bumps" phenomenon.In order to processing load problem predictability, the assessment and migration of user requests are introduced, which improve system quality of service.