In this paper, we propose a novel method which efficiently codes $4{ imes}4$ intra prediction modes in H.264/ AVC video encoding. There are nine optional prediction modes for each $4{ imes}4$luma block and 4 modes for each $16{ imes}16$luma block. To code each $4{ imes}4$ intra prediction mode, lots of bits are required. To efficiently compress the intra mode bits in H.264/AVC, the most probable mode(MPM) is estimated by using the intra modes of the adjacent blocks, since intra modes for neighboring $4{ imes}4$luma blocks are correlated. In this paper, a novel method for estimating the MPM is proposed by using the statistical distribution of intra modes of adjacent intra blocks. Experimental results show that the proposed method can achieve a coding gain of about 0.1dB.