A case of primary systemic amyloidosis with various ECG abnormalities is reported. The ECG on admission showed low voltage in limb leads, right axis deviation, small q wave in leads I and aVL and QS configulation in V(1) through V(2). Conduction disturbances were observed in intra-atrial, A-V junctional and intraventricular conductions with frequent sinus arrest associated by A-V junctional escape beats. The heart sometimes fell into complete A-V block, infrequently with supernormal conduction. In spite of markedly abnormal ECG findings, amyloid infiltration in the mycoardium, His-bundle, A-V node and other discrepancies were minimum.