Myostatin (MSTN) is a negative regulator of skeletal muscle growth. The objective of the present study was to express yak (Bos grunniens) recombinant MSTN protein in E. coli and study its characteristics of immunogenicity. cDNA encoding yak MSTN mature peptide was amplified by reverse-transcription PCR, and cloned into pET28a(+) vector and expressed in E. coli. The expressed recombinant MSTN was purified by affinity chromatography and used to prepare rabbit anti yak MSTN antibody. The results showed that yak MSTN mature peptide gene contained 330 bp nucleotides coding 109 amino acids. Content of the target protein accounted for 21% of the total expression products when MSTN-pET28a(+)-BL21(DE3) bacterium was incubated in LB medium with 0.1 mM IPTG for 6 hours. The molecular weight of the purified yak MSTN recombinant protein was 16.5 kDa, exhibiting excellent immunogenicity as shown by ELISA. The obtained recombinant MSTN of yak is suitable for further analysis of yak MSTN functions.