Recently, the role of myostatin (MSTN) in controlling insulin resistance (IR( has been known. The aim of this study was to determine acute and delayed response of MSTN and IR to circuit resistance exercise. For this purpose, 12 healthy men volunteered and participated in 2 sessions of the resistance exercise and control with one-week interval. After a session to instruct how to perform resistance exercise and after measuring one repetition maximum (1-RM), circuit resistance exercise program was performed including 7 movements with 3 sets of 15 repetitions at 55% 1-RM. In each session, blood samples were collected before, immediately after, 1 hour after and 24 hour after the exercise to measure myostatin, glucose and insulin concentration and IR was calculated. Using 2×4 analysis of variance (ANOVA) with repeated measures, exercise time had an insignificant effect on plasma myostatin concentration while plasma myostatin concentration increased immediately after the exercise and 1 and 24 hours after the exercise decreased gradually. Exercise time had a significant effect on plasma glucose and insulin concentration and IR, that is, plasma glucose and insulin concentration and IR increased immediately after the exercise and 1 and 24 hours after the exercise decreased gradually. Interaction of session and time had an insignificant effect on plasma myostatin and glucose concentration, but a significant effect on plasma insulin concentration and IR. In conclusion, circuit resistance exercise cannot have remarkable effects on acute and delayed response of MSTN and IR.