Abstract: Using the methods of PCR amplification and sequencing, the polymorphism of myostatin (MSTN) gene were detected in 12 Dulong gayals.The results showed that, 1128 base pairs existed in the 12 samples, 1 polymorphic site was observed with 2 haplotypes, G (75%) and A (25%) and the average number of nucleotide differences (k) was 0.409 in Dulong cattle. The findings indicated that MSTN gene of Dulong gayal had a low level of gene diversity, but it did not inherit independently, with some genetic communication with yak, demonstrating a loss of genetic resource in Dulong gayal and effective measures needed to protect the gayal population.