Abstract: For the artificial fish simulation, there exists a problem of huge workload demands and strict request for hardware resources to model objects and behaviors to achieve animation. In this article, a new simplified model objects method is put forward to solve this problem, based on the combining of physical and biological mechanism. This method is used to simulate the movement of fishes. In the simulation, each individual fish is defined as an independent agent, which is restrained by the physical mechanism of group activities and model of biological perception of an individual. According to the kinematics knowledge and the tweening animation technique, the problem of coordination between an individual and the overall is solved well, and good simulation of three-dimensional swimming of fishes on PC is achieved.