The purpose of this study finds out the effect of red ginseng extract(1.0 g/kg) on bis(tributyltin)oxide(TBTO)(10, 20 and 40 mg/kg) which poisons against some organs like thyroid gland, liver, kidney, testis, ovary. Serum immunity and sex hormone activity of rats are examined by gastric tubing for 3 weeks. The weights of each in treated group were increased, especially liver in females and those of testis in males were signignificantly increased at 10, 20 and 40 mg/kg (P<0.05, P<0.01). In group treated with TBTO(10, 20 and 40 mg/kg) for females, the serum IgG level was significantly reduced in comparison with control group(P<0.05). The group of females which were poisonned by TBTO and rGe was significantly recovered in TBTO 10 mg/kg + rGe 1.0 g/kg and TBTO 20 mg/kg + rGe 1.0 g/kg. In case of sex hormone activity of each sex, the estradiol activity of females and testosterone activity of males were signignificantly decreased rather than the control group. And control group by bis(tributyltin) oxide and red ginseng extract is just increased estiradiol activity.