Digital video quality assessment plays an important role in video compression , processing and video communications. A method of video quality assessment based on gradient and motion estimation was proposed according to the existing evaluations and human visual system. The new method takes into account the characteristics of the edge information, the temporal correlation between frames, and effects of the scenes′ contents changes on the quality of the video. The experiments results show that it is coherent to the human eye's visual effects on the distortion video based on H.264.