Objective To explore the effects of gestation exposure to dibutyltin dilaurate (DBTD) on the activity of enzymes in the testis and the spermatogenesis function in the mature male offspring of Wistar rats. Methods The pregnant rats were treated with DBTD by gavage at the doses of 0, 10, 20 and 30 mg/kg for days, from 12th-20th days of gestation. On 70th postnatal day, 10 male offspring rats were selected randomly from each group for measurements of the viscera coefficient of testis and the sperm count in epididymis, the activity of enzymes of testis was determined by spectrophotometry. Results There were no significant differences seen in the body weight gain of pregnant rats from days 12-20 of gestation, litter size, sex ratio of fetuses and body weight of male offspring rats between the experimental groups and the control group. The testis weight and viscera coefficient of testis in 30 mg/kg group increased significantly compared with the control group(P