Objective: Myostatin has recently been proposed as an important factor that not only regulates skeletal muscle mass, but also body fat mass. The aim of our study is to explore serum myostatin levels in overweight patients and its association with metabolic-related characteristics. Methods: 40 overweight patients and 40 normal weight controls were recruited, and serum myostatin were measured by ELISA methods and the relationships between myostatin and metabolic-related parameters were investigated. Results: Serum myostatin concentrations were significantly increased in overweight patients compared with normal weight controls (10.99±1.99 vs. 9.75±0.96 ng/ml, P=0.001) and positively correlated with body weight (r = 0.272, P=0.015), BMI (r = 0.263, P=0.018), waist circumference (r = 0.291, P=0.009), hip circumference (r = 0.336, P=0.002) and TNF-α (r = 0.611, P Conclusion: Serum myostatin levels in overweight patients are notably increased and positively correlated with BMI, body weight, waist and hip circumference, TNF-α, suggesting myostatin is a metabolic regulatory factor.