Abstract: In order to increase the encoding speed while maintaining the efficiency of H.264 coding, this paper proposed a fast intraprediction mode selection algorithm for 4×4 blocks. It utilized the existing transform coefficients in the prediction process to obtain the local edge direction strength for each 4×4 block. Then, only some of highprobability modes, instead of all intra 4×4 modes, were chosen for the best mode's search. Experimental results show that the proposed algorithm can significantly reduce the complexity of intra prediction with only negligible loss of coding efficiency. Key words: video coding; H.264; intraprediction; RDO