Objective To understand the genotypes and nucleotide polymorphisms of Echinococcus granulosus metacestode from humans and sheep in Tianjun region,Qinghai Province. Methods The specific primers were designed according to the cox1 and nad1 genes of E.granulosus mitochondrial genome sequences accessed by GenBank.The primers were used to detect the cyst samples from 16 sheep and 2 humans infected with E.granulosus in Tianjun region of Qinghai Province by PCR,then the PCR amplification products were sequenced,the genotypes and nucleotide polymorphisms of the cox1 and nad1 genes were analyzed.Results The 18 isolated samples all belonged to E.granulosus G1 genotype.Among all the isolates,9 haplotypes ex-isted in the cox1 gene with 16 nucleotide mutation sites,and there were 0 to 5 nucleotide differences with the highest variation rate of 0.31%,whereas 7 haplotypes occurred with 15 nucleotide mutation sites,and there were 1 to 8 nucleotide differences with the highest variation rate of 0.89% for the nad1 gene.Conclusions The epidemic genotype of E.granulosus is G1 in hu-mans and sheep in Tianjun region of Qinghai Province,and the nucleotide polymorphisms of the cox1 gene were more abundant than those of the nad1 gene,and the resolution of the nucleotide polymorphisms of cox1 gene is higher than that of the nad1 gene used in E.granulosus isolates.