A motion mode driven adaptive group of pictures(MDA-GOP)is proposed to reduce the coding performance loss that is caused by motion compensation temporal filtering(MCTF)using fixed group of pictures(GOP)structure when the video sequence contains fast motion or complex motion. The MDA-GOP adapts to wavelet-based video coding. The main idea is as follows: every four motion fields are extracted to decide the motion mode of the GOP with initial size 16; The final GOP size is then determined by the motion mode; Finally

MCTF and coding are performed in the final GOP structure. Experimental results compared show that the proposed MDA-GOP structure achieves 0.05-0.50 dB PSNR gain in comparison with the fixed size GOP structure

and that the coding time is saved at least 40% compared with the adaptive GOP structure that is decided by mean square error.