Abstract: Color is a kind of significant features in image retrieval. A new kind of image feature, namely Dominant Color Moment (DCM), which reflects spatial information of Dominant Color (DC), is taken into account. A feature model of DC features is also established. Several methods of similarity measurement based on the improvement of quadric form distance function are presented and compared. One of these methods, DCME, shows good effect in the CBIR experimental system implemented by means of WWW distribution.