To apply the particle filtering algorithm in video target tracking, reduce its computation and improve the adaptive and robust ability of this algorithm, the concept of equal effective particle number (EEPN) was proposed to reduce the steps of re-sampling, thus reduce the computation. To make the algorithm be less sensitive to brightness, the HSV color model was used instead of RGB color model to identify the target. In the end of this paper, some experiments were done, and the results show that our methods are effective to reduce computation and improve the steadiness of algorithm.