Previously we have reported that administration of Korean red ginseng water extract (KRG-WE) plays both preventive and therapeutic roles in testicular toxicity of guinea pigs exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Further study was carried out to verify the beneficial role of Korean red ginseng in TCDD-induced testicular toxicity with different animal species by different route of administration. Korean red ginseng crude saponin (KRG-CS) was prepared by Diaion HP-20 adsorption chromatography. One hundred twenty rats (Sprauge Dawley, 200${pm}$10 g) were divided into 6 groups. The normal control group (NC) received vehicle (i.p.) and saline (p.o.). Predetermined dosage of TCDD (40 $mu extrm{g}$/kg b.w., i.p.) was administered to single TCDD-treated (TT) and test (CS) groups. KRG-CS was admin-istered (p.o.) at daily doses of 5 (CS5), 10 (CS10),20 (CS2O) and/or 40 mg/kg b.w. (CS40) for 5 weeks, starting 1 week before the TCDD-exposure. Body weight gain, organ weights, and sperm quality were investigated. Decrease in body weight gain induced by TCDD was greatly attenuated by KRG-CS in a dose-dependent manner. Testicular weight, sperm head counts and ratio of sperm with progressive movement in TT group decreased significantly but those parameters were improved by the treatment of KRG-CS in a dose-dependent manner. This result led us to conclude that crude saponin might be the active ingredient of Korean red ginseng that attenuates the testicular toxicity induced by TCDD.