We investigated the effects of the oral administration of Korean red ginseng (KRG) on morphologic change and function of liver in dogs. Fifteen adult mongrel dogs (n=15) were divided into three groups: a control group (40% hepatectomy, untreated), a 250 group (40% hepatectomy, 250 mg/kg of KRG, PO), and a 500 group (40% hepatectomy, 500 mg/kg of KRG, PO). The liver regeneration, histologic findings, CBC (WBC, RBC, PCV, and PLT), and liver function tests (AST, ALT, GGT, ALP, LDH, and T-bil) were examined during experiment. The liver regeneration rates were higher in treated groups than in the control group. But, there were no significant differences. All hematological values were within normal ranges except leukocyte counts for 3 days postoperatively. The levels of AST and ALT in the treated groups were significantly decreased compared to that in the control group (p<0.05). The numbers of degenerative cells and area of connective tissue were significantly decreased in the liver of the dog with KRG administration (p<0.01). On the basis of these results, we could conclude that KRG accelerate the liver regeneration and ameliorate the liver injury after hepatectomy in dogs.