The new development concept is the main content of the thought on socialism with Chinese characteristics for a new era of Xi Jinping. It is a baton that guides the high quality development of countries and regions. The coordinated development of Sichuan and Chongqing, represented by the ChengduChongqing urban agglomeration, will soon become another important growth pole after BeijingTianjinHebei, Yangtze River Delta and GuangdongHongkongMacao. Based on“innovation,coordination,green,open and sharing”, we can construct synergistic development index of SichuanChongqing, which contains five development concepts. Using the data from 2008 to 2017 to calculate, we are able to find the following conclusions. Firstly, as a whole, the total index of synergistic development has increased year by year, but the rate of increase has declined. So there is a large room for improvement of synergistic development of these two areas. Secondly, from subindicators, the improvement of the innovation development index and the green development index in the past decade is very obvious. The coordinated development index and the shared development index are slowly rising, while the open development index shows a trend of rising first and then falling. Thirdly, in order to narrow the gap between the developed regions such as BeijingTianjinHebei, Yangtze River Delta and GuangdongHongkongMacao, we need to persist in innovation development, focus on coordinated development, lead green development, expand open development and achieve shared development, and deepen the synergistic development of Sichuan and Chongqing, so that Chongqing is able to play a supporting role in the development of western region in the new era, a driving role in the coconstruction of “the Belt and Road”, and a demonstration role in the green development of the Yangtze River Economic Belt.