Objective To study the protective role of danshensu in liver injury and the pathogenesis.Methods Acute liver injury was induced by intragastric thionletamide(TAA).The rats were randomly divided into 3 groups:normal control group(N),TAA treated group(TAA),and TAA plus DSS treated group(TAA+DSS).Liver function was evaluated by ALT,LDH and endotoxin in plasma.The liver homogenate levels of thromboxanes B_2(TXB_2)and 6-keto-PGF_1α would demonstrate the changes of hepatic microcirculation.HE showed histomorphology and Weigert′s staining showed microthrombi.Results The levels of ALT,LDH,endotoxin,TXB_2 in TAA+DSS group significantly decreased(vs TAA group,P<0.05 or P<0.01),nevertheless the levels of 6-keto-PGF_1α significantly increased (P<0.05).HE showed:infiltration of inflammatory cells in TAA+DSS group reduced and damage of hepatocytes significantly lighten(vs TAA group,P<0.05);hepatocytes inflated and sinusoidal narrowed,alarge number of inflammatory cells infiltrated and point or slice necrosis in TAA group.Weigert′sstainingshowed microthrombi inTAA+DSSgroup significantly reduced(vs TAA group,P<0.01).Conclusion Danshensu protects the liver from injury by the decrease of endotoxin amount and the improvement of hepatic microcirculation.