Motion estimation is a key technique in video compress and coding. Based on the analysis of the character of motion vector, a novel block motion estimation based on immune clonal selection (BMEICS) is proposed in this paper with some strategies like prediction of initial search point, Gray encoding and effective stop criteria. BMEICS synthesizes the character of block motion estimation and that of global search, diversity, and no prone to premature in immune clonal selection. It speeds up the process of motion estimation while maintaining the average with little loss. Experimental results show that BMEICS obtains almost the same as the full search algorithm with fewer search points, and outperforms the existing fast block-matching algorithms for most sequences in terms of speed and quality. Furthermore, BMEICS is applicable to all types of video sequences in spite of the degree of motion.