Abstract: The ABO blood types of 1260 randomly selected samples of six ethnic groups in Western Guizhou were analyzed. The gene frequencies of Bouyei 、Miao 、Man and Bai close each other, in com- parison with these groups Yi and Gelo have great differences. The distribution of ABO blood types in Bouyei 、Miao 、Man and Bai is O >B>A >AB, while it is O >A >B>AB in Yi and A >O >B>AB in Gelo. The study demonstrates that the ABO phenotypes' distribution and gene frequencies are com- paratively stable in this area and the distribution conforms to Hardy-Weinberg balance.

Key words: ABO; Gene frequency; Ethnic group