Why is the relationship between Japan and China so volatile that it keeps fluctuating between deteriorating and improving during the last half century? Why does criticism of Japan over historical issues repeatedly converge and reemerge? The reason lies in the constant power struggles taking place inside the Chinese Communist Party itself. An examination of various cases and documents dating from the period of normalization of diplomatic relations between Japan and China from the 1970s to the present day will clarify how the Chinese political system is closely related to its diplomatic policies towards Japan.