关键词: 计划生育基本国策, 人口长期均衡发展, 调整完善生育政策, 单独二孩政策

Abstract: The paper reviews the background and historical process of China's basic national policy of family planning，analyses the new situation and new features of China's population and development，and summarizes the strategic tasks and safeguard mechanisms of maintaining the long-term balanced development
of China's population． China now allows couples to have a second child if either parent is an only child． The paper also introduces the significance and the progress of the policy relaxation． China's family planning over the last 40 years has helped create the external balanced development of population with economy，society，resources and environment． However，problems concerning quantity，quality，structure and distribution of population will crop up in the first half of this century． The external and internal balanced development of China's population in the second half of this century largely depends on the current and future fertility level，calling for scientific and appropriate policy making． As the objective of China's population development is turning from cubing population growth into promoting long-term balanced development of population，China's family planning programme must keep up with the new trend and adopt a new model．

Keywords: Basic National Policy of Family Planning, Long-term Balanced Development of Population, Adjustment and Improvement of Fertility Policy, Two-child Policy for Couples if either Parent is an Only Child