China's miraculous economic growth in over 30-year reform period has so far been rooted in the demographic dividend-namely, the extra growth sources resulted from its fast demographic transition. However, as working age population reaches its peak in about 2013, China is running out such dividend and urgently seeking new sources in order to maintain sustainable growth. This paper provides empirical evidence of demographic transition's contribution to economic growth and of the trend of diminishing demographic dividend, explores the mechanism of demographic transition spurring economic growth, and draws implications for policy options. <<