Abstract: A retrospective review was made of recards and specimens of 23 cases of sudden death without focus. No evidence of new problems in pathology was obtaind, and no pathologic change in the AV node and the bundle of His were found. In order to try to find out the true cause of mortality, we studied the specimens again with optical microscopes, considering that it is unhelpful to use electron microscopes to perform autopsy of the bodies which died two days a go. In this study we analysed the data on the heart and the lungs of 23 cases. Although no mortal focus was found it is believed that the mortol organ was the heart. I also agree that the histopathology of early myocardial anoxia is crucial for diagnosis. Therefore it is of higher diagnostic value to regard such histopathologic changes as waveness myocardial fibers, band degeneration of myocardial fibers and fragmentation of myocardial fibers as the basis for diagnosis of cardic death.