The general objective of this study is to examine the effect of fraction with bradykinin potentiating activity isolated from cobra snake on the LPO and its relation to free radical in the liver, kidney and testis of rats. The content of lipids, TBARS, GSH, calacium and zinc and the activity of SOD were measured. The results indicate that injection of rat with the venom fraction (1mg/kg body weight) induced a decrease in the lipids in liver, but GSH and SOD activity were increased in kidney and testi. The tissue content of calcium was increased in kidney, however zinc was increased in testis and decreased in the kidney.