Objective : In order to investigate the effect of Curcumae Longae Rhizoma(CLR) extract on the hepatocellular carcinogenesis and acute liver damage induced by diethylnitrosamine(DENA) and $CCl_4$ in rats. Methods : Experimental groups were subdivided into four; normal group (Nor), acute liver damage and hepatocellular cancer inducing control group (Con), and CLR extract 200mg/kg/day (CAA) or 400mg/kg/day (CAB) administered groups to Con. Thereafter the changes of the body weight, the liver weight and the weight of liver/100g body weight, total cholesterol, HDL cholesterol, triglyceride, the activities of AST, ALT, ALP, LDH, AFP, SOD, catalase were measured. And we observed by optical and electron microscopy. Result : 1. The body weight was decreased in Con compared with Nor for 5 weeks, but increased in Con compared with Nor from 6 week to 9 week. During experimental period of total 9 weeks, CAA and CAB were increased compared with Con. 2. The liver weight was increased significantly (p<0.05) in Con compared with Nor. The weight of liver/100g body weight was increased significantly (p<0.05) in Con compared with Nor and decreased significantly (p<0.05) in CAB compared with Con. 3. The level of total cholesterol was increased in Con and CAA compared with Nor, but there was not statistically significant. The level of triglyceride was decreased in Con compared with Nor. But increased in CAA and CAB compared with Con. The level of HDL-cholesterol was significantly increased (p<0.05) in CAA and CAB compared with Con. 4. The activities of AST, ALT were increased in Con compared with Nor, but decreased in CAA compared with Con, significantly decreased (p<0.05) in CAB compared with Con. 5. The activities of ALP, LDH were increased in Con compared with Nor, but decreased in CAA and CAB compared with Con. 6. The activities of AFP was increased significantly (p<0.05) in Con compared with Nor, but decreased significantly (p<0.05) in CAA and CAB compared with Con. 7. The activities of SOD were increased in Con, CAA and CAB compared with Nor, but decreased in CAA and CAB compared with Con. The activities of Catalase was more increased in CAA and CAB compared than Con. 8. The results of light microscopical observation, a number of hepatocytes were damaged in Con compared with Nor and CAB. 9. According to the electron microscopical observation, irregular nuclear membrane, condensed nucleoplasm was observed in Con, the experimental group was observed in the nucleus of the well-preserved and evenly developed nucleoplasm. Conclusions : These results suggest that administration of CLR extract suppress or retard on the hepatocellular carcinogenesis and acute liver damage induced by DENA and $CCl_4$ in rats.