A T-->A mutation in the promoter region of porcine myostatin (MSTN) gene has been identified in previous work. Associations of the myostatin genotypes with growth traits are unknown in swine. The present study attempts to analyze the relationship of the mutation with the growth traits which included body weight at 60 d (BW60), average daily gain from 25 kg to 60 kg(ADG1), average daily gain from 60 kg to 100 kg (ADG2) and average daily gain from 25 kg to 100 kg (ADG). Data from 165, 275, 276 and 276 unrelated individuals respectively were collected from three different swine breeding companies. Detections of the mutation were carried out by PCR-RFLP approach. The effect of MSTN genotypes (TT and TA) on growth traits was estimated by GLM procedure. The results showed that for ADG2, individuals with TA genotype were higher than those of TT genotype (P = 0.052), indicating a positive effect for A allele. For BW60, ADG1 and ADG, the effect of porcine MSTN genotype was non-significant (P > 0.1). Studies are still necessary for examining the effects in "double-muscled" pigs.