Abstract: CBIR(Content Based Image Retrieval) which indexes images or video shots desired from large image or video library, is becoming a more and more important technique in large image database organization and management. In this paper, we reviewed the development of CBIR and discussed some main techniques of CBIR, including color index, shape index, texture index (which are used in image retrieval) and shot detection, mosaic, dominant motion estimation and layered representation (which are used in video retrieval).