— MPEG-2 to H.264/AVC transcoding is an important module for video recoding in digital TV applications. For pixel domain transcoding, MPEG-2 bitstream is decoded and then reencoded by H.264 encoder. Since the behavior of the decoded video is different from the original video, in this paper, the performance of each coding mode is analyzed to select the effective coding tools. It is shown from the analysis that transcoding with motion estimation with only one reference frame and 16x16 block size and deblocking filter can achieve almost the same video quality with only 19% of the computation. The analysis result could be an important reference for the implementation of MPEG-2 to H.264 transcoder.