Objective To study the genetic polymorphism of mtDNA D-loop and microsatellite loci in Tibet mini-pigs in order to evaluate their background and lay a molecular basis.Methods Differential primers to amplify the mtDNA D-loop and ten microsatellite loci in the Tibet mini-pigs were used.Then mtDNA Dloop from gel was purified and sequenced.PAGE was used to separate the alleles of microsatellite loci in the Tibet mini-pigs.Results Analysis of polymorphism of mtDNA D-loop in Tibet mini-pigs showed that there was no change in the mtDNA D-loop.The polymorphism of 6 microsatellite loci in 30 Tibet mini-pigs was high with a mean polymorphism information content(PIC) of 0.584 and mean rate of heterozygosity(H) of 0.573.Conclusion MtDNA D-loop in Tibet mini-pigs presents no diversity which proves that it is consistent with other seeds of pigs in evolution and inheritance.The average rate of microsatellite loci in Tibet mini-pigs proves that this seed is pure.