Abstract: There is much difference between historical background，causation and process of the demographic transition in B ICS countries and their European counterparts. Especially， the differentiation between the five countries in population efficiency during the demographic transition makes the comparative study of the five countries demographic transition far more significant than the implication of a mere demographic examination. The article examines the process and changes of demographic transition in the B ICS countries，especially the formation of the population trap under the context of straining relationship between population and resources ，and the process，levels and characteristics of demographic transition in a comparative perspective. Based on current status of population changes and dynamic trends in the five countries，demographic factors of international co mpetitive power of the five
countries are discussed. The article maintains that enhancing and keeping China's future international competitive power depends on reversing the trap of population low efficiency ，having thorough top-level design with national strategic height，and achieving the full right for people of democratic reproductive decision- making.

Keywords: BRICS, Demographic Transition, Population Efficiency

摘要： "金砖五国"的人口转变在历史背景、因果关系与过程差异性等方面都不具备欧洲模式与特性。特别是五国人口转变中所实现的"人口秩序"和"人口效率"上存在的差异性,使得五国人口转变的比较研究远远超出传统研究中单纯的人口学意义。文章解释了五国人口转变的进程与变化,尤其是在人口与资源的脆弱背景下"人口陷阱"的形成,人口转变的各自进程、达到的水平、特征及各国比较,在五国人口转变现状与动态趋势上,进行了基于五国国际竞争力比较的人口因素解释。文章认为,中国未来国际竞争力的提升与保持,取决于在多大程度上扭转"人口低效率"陷阱,取决于国家战略高度的周密的"顶层设计",更取决于公众具有充分的生育民主决策权。

关键词: 金砖五国, 人口转变, 人口效率