OBJECTIVE To explore the expression of myostatin, a negative regulator of muscle growth, in the skeletal muscle of myositis patients and its significance. METHODS A semi-quantitative reverse transcription polymerase chain reaction were performed to evaluate the expression of myostatin in the skeletal muscle of 5 Polymyositis patients and 4 healthy controls. RESULTS Expression index of myostatin gene mRNA in skeletal muscle of myositis patients was 0.62±0.393. It was similar to that of healthy controls (0.34±0.150, P = 0.199). CONCLUSION There was no change of the expression of myostatin gene mRNA in skeletal muscle between myositis patients and normal individuals.