Abstract: Abstract: According to the H.264/AVC video encoding standard,a robust video watermarking algorithm based on inter-frame mode selection has been proposed.On the foundation of selecting the mode of sub-macroblock,algorithm selected a binary digital picture as watermark image at first;After scrambling and coding the watermark image it scaned the image into one-dimensional vector and then used the binary sequence as watermark information to be embedded. Secondly, according to the value of watermark sequence,the parity of the sub-block’s number was modified along with the mode of sub-macroblock,and those sub-macroblocks whose SAD value have minimum change after modification was selected as the embedded region;Finally,the quality of video was improved by embedding the watermark into discontinuous frame and increasing the strength of the filter.Under the premise that does not affect the correct extraction of watermark,simulation results have shown that the proposed algorithm has good robustness against noise attacking and the watermarking is invisible and robust.Meanwhile,it has little influence on the bit rate,and also has good effect in the PSNR of video.