ObjectiveTo investigate the efficacy and safety of ursodeoxycholic acid (UDCA) in the treatment of drug-induced liver injury (DILI). MethodsTwo hundred and eighty eight cases of clinically diagnosed DILI patients were divided into two groups:treatment group with liver-protecting and transaminase-lowering treatment together with UDCA(750 mg/d) treatment (group A),the control without UDCA (group B). Comparison between two groups was analyzed in clinical signs,symptoms and biochemical indicators of liver function. Results In the clinical signs and symptoms,such as fatigue,vomiting,group A is more improved than in group B significantly(0.006 2 and 0.023 4,respectively).In the biochemical aspects of liver function DBil,GGT,group A was significantly better than that in group B (0.001 6 and 0.007 3,respectively). There was significant difference in TBil,DBil and GGT before and after treatment in patients with cholestasis and DILI ( 0.0002,0.0000 and 0.0008,respectively). ConclusionUDCA is safe and effective in the treatment of DILI,especially for the cholestasis-type and mixed-type.