Panax Saponin A(PSA) , one of dammarane glycosides of Korean ginseng, was labeled with $^{3}H$ or $^{14}C$ by our Previously reported Procedures of organic synthesis. Tracer studies with $^{3}H$-PSA in wino yielded the following results: 1). Oral and intraperitoneal administration of $^{3}H$-PSA resulted in the rapid appearance and prolonged retention of $^{3}H$-PSA in all organs such as liver, brain, bone marrow and spleen of mice. 2). The amount pi cellular intake of $^{3}H$-PSA was shown to have a certain level of saturation ranging from 0.4mg to 0. 7mg Per 20gm body weight of mice. Administration of $^{3}H$-PSA within the dosage of the saturation point did net give urinary excretion of 3H-PSA. On the contrary, excessive administration of $^{3}H$-PSA resulted in rapid excretion of the substance in the urine of mice.