鱼体运动特征能直观地反映水体环境质量状况，在生物水质监测中具有十分重要的意义。在分析鱼体运动模式的基础上，提出了基于鱼体骨架中心线的尾频活性模型，利用该模型获取鱼体尾频、速度、加速度等运动参数，表征鱼体游动在被监测水质中的运动活性程度。实验数据表明，模型较好地表征了鱼体当前的运动状态，为后期鱼体运动在生物水质监测中的应用提供了理论基础。

The fish motion essentially reflects the current state of water quality, so it is necessary to study the methods of obtaining the real-time dynamic motion characters of fish body in the field of biological water monitoring. Based on the analysis of fish locomotion model, the paper presents a fish activity model using the frequency of tail swing, which acquires some kinematical parameters, i.e., tail frequency, swimming velocity, acceleration and so on. The results show that the model,which can be used as the theoretical basis of the application, represents the fish motion activity accurately and efficiently in the biological water monitoring.