The concept of population security is one of the core concepts in the field of population development in the new era, as well as its extension, interpretation, and enrichment of a holistic approach to national security. Population security is not only the direct embodiment of a holistic approach to national security but also has a profound impact on political security, national defense, geopolitical security, cultural and ideological security, and socioeconomic security. China's population has undergone a fundamental transformation. The population development strategy in the new era urgently needs to integrate the perspective of population security and work together from the two dimensions of promoting population development and maintaining population security. We suggest to comprehensively implement a holistic approach to national security in the population development strategy, to strengthen population prediction and early warning, and prevent all kinds of population risks, to optimize the population development strategy to cope with the birth decline, to actively respond to population ageing and improve the ability to prevent risks, and finally to improve the population security system and promote family development to become a national strategy.

Since its founding, the CPC has lead a path of population development with Chinese characteristics in the past century, a period with revolution, construction, and reform, and formed the CPC's population thought. The CPC's population thought originated from the Marxist population thought. It sprouted during the new democratic revolution period, and gradually formed along with socialist revolution and construction. It was continuously improved in the new period of reform and opening up. It then keeps developing. The CPC's population thought systematically solves the big issue of how to achieve a comprehensive development for people in a country with a huge population like China. It is about the laws, functions, goals, concepts, methods, and guarantees of population development. This systematic and rigorous system is scientific, peoplecentered, practical, open, and national. This population thought is also the fundamental guarantee for the historic achievements of China's population development, and the scientific guide for promoting the greater achievements for China in the new era.

Based on 2017 China Fertility Survey, this paper analyzes the national fertility level, fertility intentions, contraceptive use, and childbearing and parenting services. The results show that, from 2006 to 2016, the mean ages at first marriage and first birth increased by 2.7 and 2.6 years, respectively. The total fertility rate between 2006 and 2011 was between 1.60-1.70 and fluctuated between 2012 and 2016, peaking in the years of 2012 and 2016. Compared with the curves of age-specific fertility rate in 2006 and 2011, the one in 2016 shifted significantly to the right. Affected by the selective two-child policy and the universal two-child policy, the proportion of second parity has increased since 2012, while the trend is opposite for the proportion of first parity. Since 2011, the sex ratio at birth has declined slightly. For women at childbearing ages, the ideal number of children is 1.96, while the intended number of children is 1.75. The rate of contraceptive use of currently married women at childbearing ages is 84.7%. About 80.8% of children aged 3-5 are enrolled in the kindergarten, 34.9% are in public institutions and 65.1% in private institutions. The future trend of Chinese fertility is also discussed.