This chapter examines the contribution of Sino-Japanese economic interdependence on China's moderation of the role of mass nationalism on its policymaking. It contends that the importance to China of stable Sino-Japanese economic cooperation has compelled Chinese leaders to repress periodic mass outbursts of anti-Japanese nationalism before they could harm Sino-Japanese economic cooperation. But the rise of the Chinese economy vis-à-vis Japan, and Beijing's corresponding understanding that Japanese dependence on the Chinese economy has superseded Sino-Japanese interdependence, have weakened the constraints of economic interests on China's Japan policy. The rise of the Chinese economy has eroded the contribution of economic interdependence to stable Sino-Japanese relations, suggesting a long-term trend of greater nationalist content in China's Japan policy.