Objective To discuss the relationship between the content of NO, MDA and ET in liver tissues and liver injury caused by obstructive jaundice and the protective effect of Danshen Injection on liver. Methods SD rats were randomly divided into 3 groups: normal control rats ( n =8), rats of obstructive jaundice ( n= 16), rats of obstructive jaundice treated by Danshen injection liquid ( n =16). Models of obstructive jaundice were made on rats by ligating and cutting their common bile ducts. NO 2 -+NO 3 -, MDA, ET in liver tissues, liver function and morphological changes were assayed on 7 days and 14 days after operation. Results NO 2 -+NO 3 - and MDA in liver tissues increased significantly in rats of obstructive jaundice compared with normal control rats, but they didn't increase as the time went on. ET also increased significantly as the time went on. NO 2 -+NO 3 - in the liver tissues of rats treated by Danshen Injection did not differ from that of rats without treated by Danshen Injection. MDA and ET decreased significantly in liver tissue of rats treated by Danshen Injection, and now liver injury was relieved. Conclusion Danshen Injection has a protective effect on the liver, which is possibly because Danshen can relieve lipid superoxidization reaction and improve microcirculation of liver.