Abstract: Using PCR technology,sequencing technologies and bioinformatics analysis technology to amplify and analyze the mtDNA D-loop region complete sequence of four local cattle varieties,a hybrid cattle variety,five local buffalo species and two local yak breeds.The results showed that Chinese domestic buffalo,yak and cattle breeds had rich mitochondrial genetic diversity.Based on the mtDNA D-loop sequences,the phylogeny of the representative species of buffalo,cattle,yak,wild yak,Bos Taurus,Bos indicus and rivers of India-based buffalo were analyzed.The phylogenetic relationships showed that cattle and yaks clustered into one,buffalo alone clustered into one.This means cattle have a close relationship with yaks with a distant relationship with buffalo.China buffalo belong to the swamp type water buffalo,but a small number of rivers type water buffalo gradually mixed into the China buffalo groups.Chinese cattle for the Bos taurus and the Bos indicus mixture of maternal origin;phylogenetic tree showed that the plateau yak has a close relationship with the wild yak,the lake yak has a close relationship with the domestic yak.更多