Immunosuppression in mice vas induced by intrapelitoneal injection of cyclophosphamide40mg/kg for 3 days. After administration of a decoction of Panax ginseng (5g/kg ) or Trogop-terus dung (5g/kg ), alone or 1 :1 mixture of the above two drugs at doses of 5g/kg and 10g/kg for 7 days, resulted in an increase of thymus gland weight (P