A streaming media watermarking algorithm based on synergetic neural network in the IWT domain of compressed video was advanced in this paper. A gray watermark image is serially processed into watermarking signal and embedded into a compressed videopsilas IWT domain to form watermarked video. Watermark detecting algorithm is realized by using pattern recognition method of synergetic neural network. The networkpsilas input is doubtful watermark signal and itpsilas output is the recognized result that can fulfill the watermark detection so that the watermark owner can be judged. Through the emulational experiments, this algorithm can endure some processes and has fine performance of robustness and speediness.