Abstract: We elaborate on the theoretical principle of estimating the size of accumulated couples under the new birth policy，involving four fertility release patterns and calculation procedures. Using these methods，we have estimated the scale of the accumulated couples and the numbers of new born second children. First，the number of accumulated couples would be at around 26.12 million in 2014 and vanish by 2040. Second，the proportion of accumulated couples to the couples of reproductive age would increase then decrease，and the peak proported would stand at around 7.9%. Third，the age structure of the accumulated women would be heavily at age 35 and below who have strong reproductive capacity. Fourth，the spatial distribution of fertility release would be uneven，with the urban area and the Eastern region having more accumulated couples and fertility release，and the provinces including Jianasu and Shangdong are the key provinces. Fifth，the number of fertility release would account for 30%-37% of the total accumulated children in first 5 years. Therefore，the new birth policy would have a smooth transition as long as we do the best to implement the new policy in the first five to ten years.

Keywords: New Fertility Policy, Accumulated Couples, Fertility Release, Expected Fertility, Expected Birth Probability

摘要： 文章阐述了生育政策转换过程中堆积夫妇和生育释放模式及剥离的基本概念、原理、模型，对堆积夫妇规模、年龄构成及其生育释放量进行了测算。结果发现:第一，政策实施当年全国“堆积夫妇”规模约2612万对，到2040年堆积现象基本消除。第二，堆积夫妇占育龄夫妇的比重先升后降，峰值为7.9%左右。第三，35岁及以下堆积夫妇比重占70.5%，生育释放的能力较强。第四，堆积夫妇及释放生育以城镇、东部地区较多，江苏、山东等10省区是重点。第五，政策实施最初5年累计释放的生育量占总量的30%～37%左右。通过宣传引导、分类指导、合理疏导，做好政策调整最初5～10 年的工作，即可实现生育政策的平稳过渡。

关键词: 单独两孩政策, 堆积夫妇, 堆积释放生育, 预期生育率, 预期生育概率