In the field of fabric printing and dyeing, the quality of fabric is influenced seriously by the color difference. Re-search about this has been commenced on for several years and obtained a lot of methods. A new measure based on Maha-lanobis distance is introduced. The Mahalanobis distance can be applied in color space using metric hue, saturation and in-tensity. And the coherence between this formula and CIE94 color difference equation re proved briefly.