This paper proposed a simple audio and video cross watermarking algorithmbased on ltti’s visual saliency model. Frist of all, it utilized the lowpass amplitude characteristic of audio streamingto generatewatermarking, embedded into the video streaming;Secondly, decoding the keyframe, I frame, of video streaming to obtain the Y component of YUV sequence, remarkably analyzing it; Finally, nonremarkable area is blocked into DCT, embedded intowatermarking by quantization index modulation. The experimental results show that the average PSNR of key frame, in this algorithm, is lifted by 1.678 5 dB, which relieved the contradiction of watermark invisibility and robustnessand achieved the crossprotection between the audio and video streams.