Shanghai as the Yangtze River Economic Belt in Yangtze River waterway and the eastern coast of the "t" shape structure in the intersection, connecting the two sector were inland and ocean hinterland intersection points, is the best combination of the domestic economy in the international economic cycle in great. At the same time, as one of the highest level of China's economic development, Shanghai in the Yangtze River Delta region coordinated development and the future development of the Yangtze River economic belt has a special "leading" status. This paper gives a detailed analysis of how Shanghai plays a leading role in the coordinated development of the Yangtze River Delta region, and puts forward some countermeasures and suggestions. Firstly, the article explains the city "flow" is an important factor in determining a city "leading role", "big cities group in the core city is the" flow "of the central pointed out, capital flow, information flow, logistics, technology flow, personnel flow of intersection point"; followed by analysis of Shanghai in one corner of the urban flow of intensity. Then it puts forward strategy of Shanghai in the Yangtze River Delta in the leading role to play, promote the lead in the Yangtze River Delta and the Yangtze River economic belt and achieve sustainable development of "multi upgrade. <<