随着我国人口负增长时代的到来，人口少子化、老龄化，以及劳动年龄人口减少的趋势凸显，人口红利的式微正为中国下一阶段的高质量发展带来挑战。为了确定人口负增长对我国未来区域发展可能带来的影响，本文基于第七次全国人口普查中31个省级行政区分年龄性别的人口数据，使用队列要素法，分低、中、高三个情景对自然增长状态下2020-2050年全国分省人口规模以及年龄结构进行预测。在预测结果的基础上，进一步对未来中国人口空间分布特征与变化进行分析，得出结论：

第一，中国总人口规模在2023年已经进入负增长阶段，预计人口峰值将达到14.1亿左右。在未来的30年间，总人口数量可能会在2030年至2040年之间跌破14亿大关，并在本世纪中叶降至13.1亿至13.7亿之间。在省级层面，东北、华东和华北地区省份总人口在任何情景下均持续下降，西北、华南地区省份总人口在中情景下先上升后下降，西南地区省份总人口则在任何情景下均维持上升。人口负增长的时间节点显示出地域性，较早进入人口负增长的地区多为东部和北部的经济发达省份，而后进入人口负增长的省份多为经济欠发达的南部和西部省份。

第二，未来30年内中国人口分布依然维持了以胡焕庸线为界东多西少的总体格局。如果按中情景计算，胡焕庸线以西人口占比从2020年的约6.5%上升至2050年的约6.89%，总人口在全国人口负增长的大背景下依然增加了约35万，而同期东部总人口却减少了约7400万，显示出人口东降西升的趋势。人口规模较大的东部、北部省份面临人口负增长态势，人口位序下降明显，而人口规模、位序增长的多为人口规模较小的西部省份，呈现出“北降南升，东降西升”的态势。这一变化表明，中国人口的空间分布格局虽然在可见的未来都难以突破，但胡焕庸线两侧人口总量的巨大差异可能会有缩小的趋势。

第三，从2020年到2050年，我国15-64岁劳动年龄人口比例在三种情景下均呈现负增长趋势，65岁以上老年人口比例则呈现正增长趋势，14岁以下少儿人口比例先降后升。省际差异方面，我国东部和北部各省的老龄化程度最严重，它们均于2030年之前进入超老龄化社会，我国西部和南部各省的老龄化进程则相对缓慢，进入超老龄化社会的时间节点均晚于2032年。

由于本文未将人口迁移纳入预测范围，以及对总和生育率、预期寿命的设定不能考虑到所有可能的情况，使得预测结果可能存在一定的误差，在未来的研究中应当作出相应改进。

With the advent of the era of negative population growth in China, the trend of fewer children, aging and the reduction of the working age population has become prominent. The decline of the demographic dividend is bringing challenges to China's high-quality development in the next stage. In order to determine the possible impact of negative population growth on China's regional development in the future, based on the age and gender specific population data of 31 provincial administrations in the seventh national census, this paper uses the queue element method to predict the national provincial population size and age structure from 2020 to 2050 under the state of natural growth in three scenarios: low, medium and high. Based on the prediction results, this paper further analyzes the spatial distribution characteristics and changes of China's population in the future

First, China's total population has entered a negative growth stage in 2023, and the peak population is expected to reach about 1.41 billion. In the next 30 years, the total population may fall below the 1.4 billion mark between 2030 and 2040, and fall to 1.31 billion to 1.37 billion by the middle of this century. At the provincial level, the total population of provinces in the northeast, East China and North China continued to decline in any scenario, the total population of provinces in the northwest and South China first increased and then decreased in the middle scenario, and the total population of provinces in the southwest maintained an increase in any scenario. The time nodes of negative population growth show regionality. The regions that first entered the negative population growth are mostly economically developed provinces in the East and North, and then the provinces that entered the negative population growth are mostly economically underdeveloped southern and western provinces.

Second, in the next 30 years, China's population distribution will still maintain the overall pattern of more in the East and less in the West bounded by the Hu Huanyong line. If calculated according to the medium scenario, the proportion of population in the west of huhuanyong line will increase from about 6.5% in 2020 to about 6.89% in 2050. The total population will still increase by about 350000 against the background of negative population growth in China, while the total population in the East will decrease by about 74million over the same period, showing a trend of population decline in the East and rise in the West. The eastern and northern provinces with large population size are facing the trend of negative population growth, and the population order has decreased significantly, while the population size and order growth are mostly in the western provinces with small population size, showing a trend of "declining in the north and rising in the south, declining in the East and rising in the west". This change shows that although the spatial distribution pattern of China's population is difficult to break through in the foreseeable future, the huge difference in the total population on both sides of the Hu Huanyong line may have a narrowing trend.

Third, from 2020 to 2050, the proportion of the working age population aged 15-64 in China showed a negative growth trend under the three scenarios, while the proportion of the elderly aged over 65 showed a positive growth trend, and the proportion of children under 14 first decreased and then increased. In terms of inter provincial differences, the eastern and northern provinces of China have the most serious degree of aging, and they all enter the super aging society before 2030. The aging process of Western and southern provinces of China is relatively slow, and the time node of entering the super aging society is later than 2032.

Because this paper does not include population migration in the prediction scope, and the total fertility rate and life expectancy cannot be set in consideration of all possible situations, the prediction results may have some errors, which should be improved in future research.