【摘要】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.