文章在多方案預測21世紀我國人口變動趨勢的基礎上，發現2016年起實施全面兩孩政策對從宏觀上減緩老年撫養比的影響要大于減緩老年人口系數的影響;而且隨著時間的推移，在2100年的影響將會進一步顯現。實施全面兩孩政策雖然會使我國在2030左右提前關閉"人口紅利"的機會視窗，但它能減緩21世紀下半葉的總撫養比，從長期看有利于人口均衡發展。實施全面兩孩政策從微觀上對增強我國家庭養老功能的影響更大，有利于提高"四二二"家庭結構比例，增強2040年后大批獨生子女父母進入高齡時的家庭養老功能，規避與生育政策有關的獨生子女不幸死亡和傷殘給家庭養老帶來的風險。

Multiple-model projections of China’s population change in the 21 stcentury suggest that the universal two-child policy implemented in 2016 macroscopically would have much larger effect on alleviating China’s old-age dependency ratio than on alleviating the old-age coefficient.Despite that the opportunity window of China’s demographic dividend would close in around 2030,the universal two-child policy could reduce China’s general age dependency ratio in the latter half of the 21 stcentury,which helps to balance the long-term population development.On the other hand,the universal twochild policy would microscopically have great effect on enhancing family care for the elderly in China,and helps to increase the share of the ‘422 ’type of families,to strengthen family care when many one-child parents become the very old after 2040,and to avoid the risk of death and disability of policyrelated only children.