Abstract: The analysis of fish swimming dynamics is of great significance to solve key hydraulic problems in engineering application such as fishway design. Using computer technology to analyze fish swimming dynamics benefits the understanding of the physiological characteristics and swimming ability of fish and its relation to the hydraulic factors. This study analyzed the swimming dynamics of silver carp using MATLAB, with emphasis on the tail-beat. The indicators included tail-beat frequency, tail-beat amplitude, swimming speed and acceleration. Compared to manual counting and manual tracking analysis method in the perspective of actual operation complexity and accuracy on the experimental data, the method of matlab on tracking fish body center line got data more effectively in accuracy and speed by analyzing the pros and cons of each method. Thus, a method of analyzing fish swimming kinetics based on Matlab will provid a powerful technique for future researchers.