ObjectiveTo investigate genetic polymorphism of 3 STR loci in Bouyei ethnic group in Guizhou.Methods The DNAs of 101 healthy unrelated Bouyei individuals in Guizhou were extracted using chelex-100 method and were multiplex amplificated by PCR technique and the denatured PAGE was used, the PCR product was typied using silver stain method. The data was statistically analysed by modified-powerstat software package. Results A total of 21 alleles and 50 genotypes were observed in the 3 loci and the distributions of these genotypes were consistent with the law of Hardy-Weinberg equilibrium. The heterozygosity(H) of CSF1PO, TPOX and TH01 loci were 0.7287,0.5423 and 0.6904; the polymorphism information content(PIC) were 0.6805,0.4479 and 0.6426; the discrimination power(DP) were 0.8782,0.7361 and 0.8563 and the probabilities of paternity exclusion (PPE)were 0.6148、0.3643 and 0.5737 respectively. Conclution CSF1PO and THOX are highly genetic polymolphism, which is valuable for population genetic research and forensic individual identification. The distrbution of gene frequencies and their area of ethnic groups have parallel relation.