There are more and more productions to be saved as digital form. In digital world, we can keep the production will not going off forever. But it also has some disadvantages that people can do a copy very easily. Watermark is an important protection method in digital media nowadays. When one media was public or put on the network,itis veryeasy to be copiedor misappropriated. The author can prove he own the media by use open algorithm and security key to extract the watermark. So one watermark technique must resist some attacks and cannot influence the quality of image. It is usually used to embed watermark in spatial domain and frequency domain. Each of them has specialized skills. In this paper, we propose an image watermark technique based on spatial domain in color image. We have some experimental results in this paper. It can prove our method can resist some attack.