An improved intra-prediction method for AVS-M, which is developed by AVS (Audio Video Coding Standard Working Group of China) to meet the requirements of multimedia applications in next-generation mobile communications, is proposed in this paper. Utilizing the spatial and temporal correlation of the video sequences, the proposed method only processes a portion of normative 9 intra-prediction modes to decide the best mode, therefore, speeds up intra prediction with some degradation in the coding gain. Moreover, a complexity-scalable technique is presented to control the complexity of intra prediction, by which the video coder is matched to the limited computational resource of communication devices. The proposed methods are verified. The results show that the improved mode-decision method can significantly save encoding time at expense of little coding loss and the complexity-scalable technique works robustly and accurately. In addition, the proposed method also can be applied to other standards, such as H.264.