The effects of cyclooxygenase 2 (COX 2) on alcohol induced liver injury in rats were investigated. Rats were randomly divided into three groups: Control group was given with corn oil plus dextrose; Model group with corn oil plus ethanol; Treatment group with corn oil plus ethanol and a selective COX 2 inhibitor celecoxib. All materials were injected into stomach through intragastric tubes. Liver samples were analyzed with histopathology, fatty staining and immunohistochemistry. Glutathione s transferase (GST) activity of liver tissue and plasma were detected. Levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum were measured. Compared with the control group, positive fatty staining cells and expression of COX 2 in liver, level of ALT and AST in serum and activity of GST in plasma were all significantly increased in the model group, but the GST activity in liver was decreased. However, these changes were all reversed in the treatment group. The results show that the model of alcohol induced liver injury in rats has been set up successfully, the selective COX 2 inhibitor celecoxib can protect against alcohol induced liver injury in rats and COX 2 may play a role in alcohol induced liver injury