Abstract: Objective To explore the effect of cyclooxygenase 2(COX-2) in the pathogeny of alcoholic liver disease (ALD). Methods A model of ALD was developed with Wistar rats by intragastric alcohol. Liver samples were collected in the end of 4th, 8th, 12th and 16th week respectively. The concentrations of triglyceride(TG), oxygen free radical (ORF), superoxide dismutase (SOD), anti-superoxide anion (ASOA), 6-ketone-prostaglandin F1α( 6-K-PGF1α), thromboxane B2(TXB2) and malondiadehyde ( MDA) in the liver homogenate were measured by biochemistry chromatometry. Pathology of hepatic tissue was observed by hematoxylin eosin，sudan Ⅳand sirius red staining.The protein and mRNA expression of COX-2 in liver tissues were examined by immunohistochemical method and reverse transcription-polymerase chain raction (RT-PCR) respectively. Results In the end of 4th ,8th ,12th and 16th week,the content of COX-2 mRNA in liver tissue of model rats were 1.29,1.70,1.92 and 3.38 times the same as normal rats(P<0.01,except for 4th week),and the expression of cox-2 protein increased also. Pearson correlation analysis showed that the COX-2 mRNA expression was correlated positively with the content of OFR,MDA,TG,and TXB2 (P<0.01),and correlated negatively with the content of ASOA, SOD and 6-K-PGF1αin the liver homogenate(P<0.01). Conclusion There is close correlation between COX-2 and oxidative stress，which plays an important role in the etiopathegenesis of ALD.