The contamination of water by metal compounds is an environmental problem. The present study is aimed to investigate biochemical studies in the liver tissue of fresh water fish Cirrhinus mrigala exposed to sublethal concentration of nickel. In the present study, the activity of Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) in the liver tissue were observed. During the sublethal concentration of nickel, the Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) were increased in the liver tissue. These results indicate the concentration of nickel damage the liver tissue of Cirrhinus mrigala.