The myostatin gene, a member of the transforming growth factor-beta (TGF-β) surperfamily, is a negative regulatory factor of skeletal muscle growth. A series of experiments were carried out by the RT-PCR method to probe the difference of mRNA expression of porcine myostatin gene in three muscular tissues, namely skeletal muscle, heart muscle and stomach smooth muscle. mRNA expression was found in all muscular tissues. mRNA expression in skeletal muscle and heart muscle was more active than in the stomach smooth muscle. This discovery is of significance to getting further into the biological function of myostatin gene, and to directing the animal breeding at molecular level as well.