Abstract：Abstract: 268 samples from 7 sheep populations including Gansu Tibetan sheep, Gannan Tibetan sheep, Qinghai Tibetan sheep, Hu sheep, Small- tailed Han sheep, Tan sheep and Minxian Black Fur sheep are involved to detect the alleles in 15 microsatellites DNA loci. The analyses of the variations in alleles, populations’ heterozygosity, the ratio of Hardy-Weinberg, genetic distance, phylogenetic tree and genetic structure are performed. As the result shows, total 187 alleles are discovered in 15 microsatellites DNA site. And 43 population-loci deviated from the Hardy-Weinberg equilibrium. The quantity measure of the deviation in Hu sheep is the largest in our investigated populations. The Populations heterozygosity analysis shows: in concerned 7 populations, Qinghai Tibetan sheep has rich genetic diversity, while Hu sheep and Minxian Black Fur sheep are lower than others. The genetic distance and phylogenetic tree results shows: the Hu sheep, Tan sheep and the Small-Tailed Han sheep's relationship are closer than other populations involved, which have the same ancestor. The genetic structure shows that the these 7 populations can divide into three genetic clusters.
