Multiple-model projections of China’s population change in the 21st century 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 21st century， which helps to balance the long-term population development．On the other hand，the universal two- child 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 policy- related only children．

1st October 2009 is the 60th anniversary of the People’s Republic of China.Over the last 60 years,particularly since the reform and opening up,China has completed the historical transition of population reproduction,becoming demographically a developed country.In order to celebrate the achievements of China’s population and demography,this issue of Population and Development Forum has invited some distinguished Chinese demographers to summarize and discuss the major changes and progress that have been made in population and demography in China over the 60 years.Professor Wu Cangping examines the irreplaceable position of demography as a discipline in China.Professor Li Jianmin highlights the unique pattern of China’s demographic transition in the context of changing population policy.Professor Wang Guixin looks at changing patterns of migration in China in the context of socio-economic changes in China.Professor Gui Shixun explores China’s old-age security system in the context of rapid aging in China.Finally Professor Yuan Xin calls for both theoretical and empirical researches on the unprecedented demographic challenges in China now and future.

This article , based on surveys and statistical data available , gives an analysis to those aged women who , due to the loss of husband, are among the inferior group .During the later half of the 20th century , the gap of the average life span between yenders(male and female) is becoming larger in quite a few developed countries and regions, but it is not the inexorable trend.Although the morbidity of the female elders is higher than that of the male , the number of the male suffering from mortal diseases is greater than that of the female .For that reason, the author stresses that a deep -going study should be made on how to lengthen the female' s average future life span and on how to reduce the behavior factors that trap the male elders in mortal diseases at the same time , as to speed up the increment of the male' s average future life span so that the female elders can be primarily taken good care of .