Abstract: Objective To study distributive frequencies and it's corelations of 6 genetical traits in Yi and Bai ethnic groups in Guizhou province. Methods According to the techniques of human population genetics and cluster random sampling, a survey on 6 genetical characters of 879 cases (Yi ethnic group 472 and Bai ethnic group 407) was carried out in October 2008，and then dealt with data using SPSS13.0 software. Results The distributive frequencies on 6 dominant traits of Yi ethnic group are 20.6％,34.3％,74.4％,76.3％,25.4％ and 60.8％ respectively; Those of Bai ethnic group are 17.2％,39.3％,64.9％,86.2％,15.5％ and 66.8％ respectively. There are very significant differences(P<0.01) between Yi and Bai ethnic groups on 3 genetical characters (eyelid, eyelash and cerumen); and significant differences(P<0.05 or P<0.01）on hair metter in sex in two ethnic groups; and significant difference（P<0.05）on two genetical characters (cerumen and Darwinian point) in sex in Bai ethnic group; Conclusions There are most people having the following characters : flat form of front hair, flexible hair matter, double eyelid, long eyelash, dry cerumen, having darwinian point and a few corelations on 6 population genetical traits in two ethnic groups in Guizhou province .

Key words: Genetical Traits, Population genetics, Yi Nationality, Bai Nationality, Guizhou