The aim of present investigation was to determine the effect of sodium arsenate on biochemical parameter of catfish, Clarias batrachus. Biochemical parameter serum glutamate oxaloacetate transaminase activity (SGOT) and serum glutamate pyruvate transaminase activity (SGPT) was increased as compared to control value at 24 hours interval due to effect of sodium arsenate. The alteration of this parameter can be effectively used for evaluate health of catfish exposed to sodium arsenate in the aquatic environment.