中文摘要：

＂环京津贫困带＂问题的破解关系到京津冀的协同发展。以往文献从多个方面阐述了＂环京津贫困带＂的形成原因,而本文则发现京津冀核心城市对周边地区产生的＂集聚阴影＂效应是＂环京津贫困带＂形成的重要原因。在此背景下,京津冀协同发展需要采取＂以地为主＂的政策,构建新的增长极,实施城市群层面的多中心空间战略。针对中国13大城市群空间结构演化的实证研究也证明多中心是城市群发展的必然趋势。因此,要抓住雄安新区建设机会,使之成为破解＂环京津贫困带＂问题的空间载体。为此提出三个方面的思考：第一,雄安新区的成功与多中心战略能否提高整个区域的绩效密切相关;第二,雄安新区需要进行科学定位,摆脱对北京的依赖,成为一个独立的中心城市;第三,雄安新区发展要将坚持政府积极引导和尊重城市发展规律相结合。

英文摘要：

The＂poverty belt around Beijing and Tianjin＂, which was put forward by the Asian Development Bank in2005, still exists and hinders the coordinated development of Beijing-Tianjin-Hebei region. This paper firstly reviewsthe causes for the formation of the＂poverty belt around Beijing and Tianjin＂, and finds most of existing literaturelacks systematic analysis and empirical tests though they try to interpret the causes from quite a few angles. Thus,the reliability of conclusions needs to be further discussed. Through exploring the influence of core cities on theeconomic growth of small cities nearby with the methods of both descriptive analysis and econometric analysis, thepaper argues that the ＂agglomeration shadow＂ from the core cities, especially Beijing, is a crucial reason for theformation of the ＂poverty belt around Beijing and Tianjin＂. In this context, the government needs to adopt the＂place-based＂policy, build a new growth pole and implement polycentric space strategy on the mega region level topromote regional coordinated development. According to the empirical study of spatial evolution and influencing factorsof mega regions in China, the trend of polycentric spatial structure can be observed. From this point of view, theXiongan New Area strategy will not only ease the pressure on Beijing, but also provide a new growth pole whichhelps to benefit the balance of regional economic growth and address the＂poverty belt around Beijing and Tianjin＂.The policy implications of these conclusions include： first, the success of the Xiongan New Area is closely related towhether the polycentric strategy can improve the performance of the entire region; second, Xiongan New Area needsscientific positioning, it should get rid of the ＂agglomeration shadow＂ resulting from Beijing and become anindependent core city; third, combining government＇s active guidance and the market mechanism is beneficial to thesustainable development of Xiongan New Area.