—H.264 video coding standard adopts different coding schemes like variable block sizes and multiple reference frames for motion estimation. Hence, H.264/AVC provides gains in compression efficiency of up to 50% over a wide range of bit rates and video resolutions compared to previous standards. However, these features incur a considerable increase in encoder complexity, mainly regards to motion estimation and mode decision. In this paper, the efficient methods aiming at speed up of motion estimation and mode decision are proposed. Experimental results show that our proposed algorithms can save the coding time about 88% compared with the reference software JM80 while keeping the video quality.