Mithun or gayal (Bos frontalis), namely Dulong cattle, only inhabits the Gaoligongshan Mountains and Drung River basin in China, one rare and endangered Bos species.To evaluate the genetic diversity and bottleneck effect of Yunnan mithun population, we screened bovine microsatellite loci to provide the genetic information for its conservation strategies and breeding programmes.A total of 126 microsatellite alleles and allele size variance in Yunnan mithun were defined.All of the loci displayed the lower genetic diversity for Yunan mithun population with overall mean of Na=7.88,PIC=0.5965 and He=0.6332, which were lower compared with beef cattle breeds.In spite of its smaller population, the normal L-shaped distribution of ailelic frequencies without any mode-shift indicated the absence of genetic bottleneck in Yunnan mithun population, inferring that Yunnan mithun population underwent the moderate gene introgression from local yellow cattle and zebu.