Abstract: Objective To investigate the hepatic tumorigenesis and aberration of lipid metabolism induced by expression of H-ras12V in hepatocytes. Methods The liver tissue and serum samples of 6-8 month-age H-ras 12V transgenic mice were collected and the histopathological analysis for liver and serum examination for ALT, total cholesterol, and triglyceride levels were performed. Results 7-month H-ras12V transgenic mice developed hepatic tumor with 100% incidence. Histopathological and serum examination showed that in the liver, specially the hepatic tumor tissues of H-ras12V transgenic mice developed steatosis significantly compared with that in the wild type mice, and the serum levels of ALT and total cholesterol increased and triglyceride decreased significantly compared with those in the wild type mice. Conclusion Ras oncogene expressing specially in hepatocytes induces hepatic tumorigenesis, liver cell injury and steatosis, which influence the lipid metabolism of whole body.