Abstract: The decline in China’s fertility since 1970s has been affected both by socio-economic development and family planning, after 1990s the influence of family planning has been overwhelmed by that of socio-economic development. It was through birth control policy at national and provincial levels that family planning has been regulated and implemented. How and to what extent does two-child policy that has been implemented in recent years affect China’s fertility? This paper makes an analysis of the effect from perspectives of lifetime fertility and period fertility of Chinese women, based on national population census and sampling survey data. The main findings are that two-child policy provides a wider and freer policy environment for women to have their children which helps to delay the downtrend of the lifetime fertility rate of women cohorts. The way in which socio-economic factors exert influence on fertility may change but need time to take shape under the new policy environment. The paper also finds that the two-child policy has significant influence on the birth of the second child, but the influence has not been strong enough to revitalize the period fertility level.