Abstract: Enzyme-histochemical investigations on autolytic rat heart were reparted. The acidic phosphatase and succinate dehydrogenase, lactodehydrogenase was reduced when 1h and 4h after death. The activity of adenosine triphosphatase was not changed during 24h after death. The author suggests that results that result of enzyme-histochemical is helpful for the estimating time of the death and diagnosis of the acute heart ischmia that wac autolysis.