In this work, we propose a new fast intra mode decision method of H.264/AVC to reduce the encoder complexity. The proposed method incorporates direction-based feature detection to filter out unlikely candidate modes for 4x4 prediction MB type. The method also avoids evoking the unnecessary mode decision process for 16x16 prediction by a threshold strategy. A new low complexity criterion is also incorporated in the method to reduce the encoder complexity further. Experimental results show the complexity is reduced to 50% on average as compared to the widely used SATD-based decision method with only little rate-distortion degradation. Another variation of this method can even reduce the complexity to about 40% with acceptable rate-distortion degradation.