Abstract: In order to strengthen the rational utilization and protection of germplasm resources of Minxian black fur sheep and Guide black fur sheep,PCR amplification and sequence analysis of Cytb,COI,ND2 and ND4 mitochondrial gene sequences of mitochondrial DNA of 6 Minxian black fur sheep samples and 5 Guide black fur sheep samples were carried out.The results showed that there were certain gene flows between Minxian black fur sheep and Guide black fur sheep,between Minxian black fur sheep and domestic and foreign sheep breeds,and between Guide black fur sheep and domestic and foreign sheep breeds.Among them,samples M1 and M4 of Minxian black fur sheep were greatly impacted by the genes of foreign hybrids.Based on the above results,the suggestions for the conservation of Minxian and Guide black fur sheep are as follows:first,avoid gene flow between Minxian and Guide black fur sheep and other sheep breeds;Second,strengthen the variety purification of Minxian and Guide black fur sheep.