A series of new derivatives of 1-(5-oxohexyl)-3,7-dimethylxanthine has been prepared for the treatment of the vascular dementia. To investigate hepatoprotective effect of these derivatives, the serum biochemical activity and the histological change of liver tissue were evaluated in carbon tetrachloride ($CCl_4$) treated rats. The activities of aspartate aminotransferase and alanine aminotransferase and the activities of total cholesterol, triglyceride and total bilirubin in 5-oxohexyl-3,7-dimethylxanthine derivatives pretreated rats were significantly decreased compared to the $CCl_4$ only treated rats but the content of glutathione S-transferase was increased compared to the $CCl_4$ only treated rats. These results indicated that 5-oxohexyl-3,7-dimethylxanthine derivatives have hepatoprotective effect in $CCl_4$ intoxicated rats.