Object:Investigate the protective effect of chitosan (CTS) on rat fatty liver.Methods:Male Sprague Dawley rats were treated with a low dose of carbon tetrachloride (CCl 4) and fed a high fat diet to produce fatty liver model.At the same time,the protective groups were treated with chitosan in different concentration,then observe the steatosis degree and determined the contents of lipids in the rats liver.Results:Combine use of CCl 4 and high fat diet caused the contents of triglyceride(TG)、total cholesterol (TC) in liver increased significantly,pathological examinations showed the swelling hepaocytes full of lipid droplets inside of them while the treated groups displayed a moderated steatosis degree and lower TG、TC compared with model group,which effects in a dose dependent mode.Moreover,this study also demonstrated that the activity of superoxide dismutase (SOD) was depleted in fatty liver,and it recovered with the reduce of TG、TC by treated with the drugs.Conclusions:The results show that chitosan have protective effect,on fat liver injury,and the protection may be associated with interfere of lipids absorption in intestine,improve liver ability of antioxidation and then increase the lipolysis and remove of TG from the liver.