In this paper, a method of fast searching I pictures in MPEG-2 system stream using long step and short step is presented. The method achieves higher speed performance comparing with the byte by byte searching method, and is applied in the design of the functions of MPEG-2 players, such as fast forward, fast backward and play backward. The implementation of these functions is described in detail. Moreover, this method can also be applied in VBR (variable bit rate) MPEG system stream, which is proposed based on CBR (constant bit rate) stream.