With the purpose to elucidate changes in heart sound and electrocardiogram in liver diseases, the author studied 85 cases of infectious hepatitis and other liver diseases, and obtained the following results. In the infectious hepatitis irrespective of age or sex, changes such as brachycardia or tachycardia, fall in blood pressures, and abnormality of heart sound can be recongized along with the progress of symptoms, but with exception of fatal hepatitis circulatory insufficiency rarely occurs in any of them. Moreover, these pathological changes are mostly reversible, and in some the murmur of heart sound remains in definitely. As for the findings of electrocardiogram, such findings as a decrease in the height of T-wave, fall in ST, elongation of QT, low potential difference and bloking of the left leg, that determine the damages in the heart muscle can be found in 47.8 per cent of acute hepatitis, in 41.5 per cent of chronic hepatitis, and in 33.4 per cent of liver cirrhosis. Furthermore, judging the liver functions from serum proteins, colloidal reaction, and serum bilirubin values, along with the diminution in the liver functions, the findings that indicate damages of heart muscles can be recognized. Likewise changes in the picture of the liver in autopsy are closely associated with the damage to the heart muscle. Similarly there seems to be a definite relationship between the liver functions and the autonomic nerve system. Again judging from the elctrocardiogram, the murmur of the mitral valve in this diseass consists mainly of hematokinetic problem due to pathological change of the left papillary muscle but not due to the organic change of the mitral valve itself.