In this paper one technique named video watermark is introduced as an important and difficult part of digital watermark technology. It embeds the special information into video data by data hiding technique,for the purpose of copyright protection, secretly communications, discrimination of digital files, and products labeling. We can utilize the research results of image watermark in the research of video watermark. For some substaintial difference between video and image, video watermark technique has some technical characteristics difference from image watermark. In this paper, we discuss the characteristics of video watermark, introduce its development situation, concretely analyze some video watemark schemes, and view its development trend.
