The aim of the present study was to examine the effect of 8 weeks of resistance training and HMB supplementation on serum myostatin levels of non-athlete men. In this quasi-experimental study, 20 non-athlete men voluntarily participated in the study and were divided into experimental group (n=10, mean age 28.75±1.39 yr, height 179.83±4.30 cm, weight 81±5.27 kg and BF% 28.65±6.40) and control group (n=10, mean age 28±2.14 yr, height 180.25±3.71 cm, weight 84.23±3.58 kg and BF% 29.21±5.97). Both groups performed the 8-week resistance training protocol (5 sets, 3 sessions per week, 50-80% 1RM intensity). Experimental group ingested 3 gr of HMB daily while placebo was used in the control group. Fasting blood samples were obtained prior to the training and 48 hours after the last session of the training protocol. The results of independent t test revealed that HMB supplementation had no significant effect on serum myostatin level. The findings of this study leads to the conclusion that HMB supplementation has no significant effect on myostatin inhibition.