Abstract: This study is shown that isoproterenal sulfate at dose more than 85mg per kilogram administered subcontaneously and venously to the rat is capale of producing cardiac and extra cardiac lesions and death. The cardiac lesion dy this drug on the basis of the localization and pathhistological characteristics is similar the ischemic nerosis (myocardia inforction), The extra cardiac lesions are consisted of the brain swelling, pulmonal edema or hyaline membranformation, centrolobular liver necrosis, cortical ischemic changes of the kidney and the other toxic manifestations.