长三角一体化自20世纪80年代开始启动，在近四十年的时间里，经过了规划协调、要素合作、机制对接、更高质量一体化发展国家战略四个阶段，一体化程度和水平明显提高，形成了作为国家战略推进各省市协同发展的良好基础。然而，长三角一体化还存在行政壁垒障碍及缺少法律制度的支撑、合作机制的市场化程度不高、中心城市作用不够突出和区域空间联系需要加强等问题。在当前经济从高速增长进入高质量发展的新阶段，长三角应努力成为我国区域经济协调发展的排头兵，为此需要打破行政区划限制，建立国家层面领导机构和市场化合作制度，构建区域一体化的新体制；以湾区作为区域发展的重要平台与载体、共同建设国家战略项目为抓手，探索形成产业项目合作共建、财政税收利益共享的新机制，促进区域一体化的深入发展。

The integration of the Yangtze River Delta has started since 1980s. In the past four decades, it has gone through four stages, namely, planning coordination,elements cooperation,docking mechanism, and national strategy of integrated development with higher quality. The integration degree and level have been significantly improved, forming a good foundation for the national strategy to promote the coordinated development of provinces and cities.
However, there are still some problems in the integration of the Yangtze River Delta, such as administrative barriers, insufficient legal support, low marketization degree of cooperation mechanism, insufficient function of central city and the undeveloped regional spatial connections. When economy development has changed from high speed to high quality, the Yangtze River Delta should strive to be the pacesetters in the coordinated development of regional economy in China. Therefore, it is necessary to break the restriction of administrative division so as to establish national leading institutions and market-oriented cooperation system and build a new system of regional integration. The Bay Area should function as an important platform and carrier for regional development. Starting with the joint construction of national strategic projects, we should establish a new mechanism for jointly building industrial projects to share the benefits of fiscal and tax revenue, and promote the high-quality development of regional integration.