Abstract: Content-based image retrieval （CBIR） has been an active research area,however,the achievements in image representation and similarity measurement are not satisfying.After going deep into the nature of image texture and human vision system,incorporating the concept of image content descriptor proposed by MPEG-7,we propose a new texture spectrum to describe the texture feature of images.Moreover,we discuss color descriptor,image similarity scheme,and the combined color and texture descriptor.Experiment results and evaluation are illustrated.