Abstract: Objective to investigate the distribution of six short tandem repeats (STR) loci in Maonan Ethnic group in Guangxi province and studied genetic relationship between 6 minorities. Methods 200 unrealated individulas were analyed by using STR genescanning marked by fluorescence. genetic distance were computed and phylogenetic tree was construted for studying genetic relationship between 6 Ethnic groups. Results The average heterozygosity(H) in the six STR loci was 0.7825; the average polymorphism information content(PIC) was 0.7324;the accumulative discrimination power(DP) was 0.99999951,and the accumulative probability of paternity exclusion(EP) was0.994575.All 6 populations were clustered into 2 group. Olunchun, Dongxiang, Seba became one group,and Yao in Jinxiu ,Miao in Rongshui ,Mulao in Luocheng, Maonan were clustered into another group.Conclusions Allele 16 in D3S1358, allele 11 in D5S818, allele 11 in D7S820 ,8 in D13S317,14 in vWA ,22 in FGA was probably the most primitive allele in repective locus. The datas obtained posses highly Genetic Polymorphisms.Genetic relation between Maonan and Mulao were closer.