Objective:To investigate the effect of human chorionic gonadotropin (hCG) on the motility of rat sperm and the fertilization rate following in vitro fertilization. Methods: hCG concentrations of 25, 50, 75 and 100 ng/mL with incubation time of 1 h and 2 h were used in medium to study sperm motility. Then, 25 and 100 ng/mL of hCG with incubation time of 2 h were applied for in vitrofertilization. After 6 h, the number of two pronuclei was counted. Obtained data was subjected to one way ANOVA and Bonferroni-Dun hoc-post test.Results:Total motility and progressive motility of sperms were increased significantly (P<0.05) in hCG experimental group with concentration of 25 ng/L and incubation time of 2 h compared to control group, however, total motility and progressive motility of sperms were decreased significantly (P<0.05) with increasing dose of hCG. Fertilization rate was decreased significantly (P<0.05) in hCG experimental group with dose of 100 ng/mL compared to 25 ng/mL and control group. Conclusions:The effect of hCG on the rat sperm motility and the rate of their fertility is dose-dependent so that hCG with dose of 25 ng/mL leads to an increase in rat sperm motility and to some extent fertilization rate.