The acute tonicity of DWP305 (Ursodeoxycholic acid : Silymarin : Fursulthiamine : Riboflavin tetrabutyrate=1: 1 : 0.1 : 0.05) was evaluated in both sexes of Sprague-Dawley rats, 6weeks old by the oral route of administration. DWP305 was not considered to induce any toxic effect on the rats in mortalities, clinical findings, body weights and gross findings. It is suggested that LD$_{50}$ value in rats would be above 5 g/kg in the oral administration. Subacute toxicity of DWP305 was examined in Sprague-Dawley rats. Four groups of rats were administered orally at doses of 0, 0.32, 0.8, and 2.0 g/kg/day of DWP305 for one month. Any significant toxic clinical symptom was not observed in the treated rats during the experimental period. Macroscopic examination on the organs of tested animals showed no abnormal findings. On autopsy, no significant changes were found in organs examined. Maximum tolerated dose of DWP305 for the rat was estimated to be above 2 g/kg in this study.y.