Abstract: This paper uses the data from the Sixth Population Census at national, provincial, prefecture and capital city levels to investigate China’s high SRB, the polarization of which is now spreading, and to discuss the latest changes of SRB in recent years. In regard to the abnormal SRB among first births, the paper analyzes the converging trend between urban and rural areas, among different regions, and from the perspective of women with different educational levels and different cohorts. It postulates that sex preference of fertility behavior at the first birth indicates that China's fertility transition has begun to enter a new historical stage and the pattern of fertility is largely motivated by social factors other than the policy ones. This paper further analyzes the distribution of gender composition for surviving children of women between 15-64 years old. The results show that the distribution is significantly and increasingly deviated from the normal one. Sex selection of fertility behavior increases the possibility of giving birth to a boy for couples over 1990 to 2010. China’s “son preference” becomes increasingly strong.

Keywords: Sex ratio at birth (SRB), SRB Among First Births, Gender Structure for Surviving Children

摘要： 本文利用“六普”数据，分别从全国、省级、地市以及省会城市等多个层面，阐述了出生性别比整体趋高、两极分化及在地市蔓延等特点，讨论近几年部分地区出生性别比的最新动态。同时特别针对新出现的一孩出生性别比失常，分析其在城乡、地区、不同受教育程度和不同代际女性间表现出的趋同特点，认为这种起点上的生育性别选择表明中国的生育转变已开始进入新的历史阶段，社会影响因素的作用强于政策因素的生育动力格局正在逐步形成。并进一步从生育结果的角度分析了15-64岁妇女存活子女的性别组合分布状况，指出这一分布明显偏离正常形态且偏离程度越来越高，1990-2010年间生育性别选择使夫妇的生男比率不断增加，“男孩偏好”表现趋强。

关键词: 出生性别比, 一孩出生性别比, 存活子女性别结构