The article deals with the investigation of validity of Color-sociometric method, i. e. method of mutual color assessment in group. The method combines qualities of clinical projective test (A.M. Etkind's color test of relationships and M. Lusher's color test) with characteristics of highly valid and reliable psychometric test. Method is determined for complete study of various indicators of group emotional state: mutual satisfaction, satisfaction by a group, group and individual self-esteem, integrity in a group, resemblance of cognitive attitudes, etc. Results of 7 investigations confirming high construct and concurrent validity as well as re-test stability of Color-sociometric method indices which can be compared with validity of psychometric tests are discussed.