The features of skin color are wide used in the areas of MPEG4, content based image retrieve and virtual reality. Presently, there are plenty of the methods of the skin color clustering and of the varieties of the clustering results. Some elementary problems of the features of skin color, such as the effect of hight source, of color constancy and of color space in which the skin color clustering is performed, are investigated in this paper. A new color space is constructed for the skin color clustering and correlation between the mage data and the color of iluminants is introduced. It is proved that high lights and shading only changes the saturation of the skin color. In this framework, both the results of the skin clustering and their applications in the facial detection and hand gesture recognition in complex background are presented.