The population thinking and practice of the Communist Party of China (CPC) is a crucial part of the history of the CPC, the history of New China, the history of reform and opening-up, and the history of socialism development. Among the thinking and practice, the implementation of family planning is a major strategic decision based on the nation's fundamental realities with large population and relatively insufficient resources. It is also an important chapter of the one hundred year of glorious history of the CPC. In order to understand and grasp China's population situation in the new period with the significant changes of population development and the gradual adjustment and improvement of the fertility policy, especially the implementation of the threechild policy and its supporting measures, we should especially attach great importance to the research of population development strategies, strengthen the research on fertility patterns and related influencing factors under the new social and economic environment, enhance the research on national strategies for positive response to population ageing, increase the research on population migration and social integration, consolidate the research on profound impact of scientific and technological progress on population development, and reinforce the study on connotation and realization of the basic state policy of family planning in the new era.

As expected，the universal two-child policy has brought about a surge in births in China， which is largely consistent with previous projections．While the number of women at childbearing age decreases，there is still a significant increase in births．To ensure the implementation of the universal two-child policy，a reform on the management of family planning service has been launched and a portfolio of systematic complementary policies has been gradually announced．For the long-term balanced population development in China，five essential topics need more attention from researchers． First，we should respect the laws of population development and keep the fertility rate at an appropriate level．Second，we should better understand the relationship between population and social development and implement social policies that facilitate a family-friendly environment．Third，we should further explore the interrelationship between population and economy．Fourth，we should investigate the relation- ship between migration and urbanization process，proposing innovative plans for population distribution．Finally，we should also be updated with the new trends of world population development，under- standing China's population development from a comparative perspective．China is now at a tipping point in the history of population development．The ground-breaking policies and reforms，such as the practice of family planning and reform-and-opening，provide great opportunities for all demographers to study and enrich population development theories．

 At the start of 2016，CPC Central Committee and State Council issued a decision on imple- menting a comprehensive two-child policy，reforming and improving the management of family plan-
ning services．This paper reviews theoretical and practical perspectives of the decision and discusses the what and the why of the two-child policy．In carrying out and implementing the decision，the major tasks involve organizing and implementing the two-child policy in accordance with the law，reforming maternity services management system，strengthening maternal and child health and family planning services，improving family planning rewards support system，strengthening organizational leadership， strengthening grass-roots work，and improving childbearing security．Family planning policy is a long- term basic national policy in China; however，China’ s future family planning work needs to be reorient- ed to achieving demographically an appropriate scale，high-quality，structure optimization，and rational distribution，and to forming a multi-governing structure of the government，society and the citizens．

At the start of 2016，CPC Central Committee and State Council issued a decision on imple- menting a comprehensive two-child policy，reforming and improving the management of family planning services．This paper reviews theoretical and practical perspectives of the decision and discusses the what and the why of the two-child policy．In carrying out and implementing the decision，the major tasks involve organizing and implementing the two-child policy in accordance with the law，reforming maternity services management system，strengthening maternal and child health and family planning services，improving family planning rewards support system，strengthening organizational leadership，strengthening grass-roots work，and improving childbearing security．Family planning policy is a long- term basic national policy in China; however，China’ s future family planning work needs to be reorient- ed to achieving demographically an appropriate scale，high-quality，structure optimization，and rational distribution，and to forming a multi-governing structure of the government，society and the citizens．

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．