In the long-term theoretical thinking and practical exploration, Xi Jinping proposed a series of important expositions on coordinated regional development. By analyzing his work and practice in urban and rural areas, provinces and the nation, Xi Jinping’s key expositions on coordinated regional development for a new era experienced three phases: deliberation, germination, and development. In the first phase, Xi Jinping has deliberated on how to relieve poverty in underdeveloped urban and rural areas. In the second, Xi Jinping explored the coordinated development of developing and developed regions in provinces. In the third, Xi Jinping proposed the coordinated regional development strategy in China. With the expansion of coordinated regional development in practice and pattern, Xi Jinping has deeper understanding of coordinated regional development, from the endeavor of ″weak birds flying first″ to the coordination between ″mountains and seas″, and finally the ″comprehensive coordination″ came into being. Xi Jinping’s important expositions, a scientific, complete and logical theoretical system, address a series of major issues concerning China’s coordinated regional development for a new era, including its fundamental position, source of driving forces, development ideas and paths as well as working methods. Xi’s important expositions are presented as follows: taking improving people’s well-being,promoting all-round human development and realizing inclusive growth as the starting point for the coordinated regional development based on the people-centered philosophy; accelerating the transformation of external support to endogenous development, going beyond development assistance, and boosting sustainable regional development; helping under developed areas in a comprehensive way based on regional growth poles and their polarization effect and diffusion effect; enhancing regional comprehensive strength by breaking down administrative barriers and cutting system transaction costs based on inter-regional cooperation; exercising the dynamic comparative advantages of the region for better coordinated development via internal and external cooperation and foreign collaboration by assisting old revolutionary base areas, areas with large ethnic minority populations, border areas, and poor areas for development and more opening up to the outside. As a vital component of Xi Jinping’s thought on socialism with Chinese characteristics for a new era, Xi Jinping’s major exposition was formed under the impetus of regional development practices since the 18th National Congress of the CPC. It holds great theoretical and practical significance. On the one hand, Xi Jinping’s important expositions inherit and develop China’s thought on regional development, promote Marxist political economy, enriching the theoretical system of political economy of socialism with Chinese characteristics for a new era. On the other hand, under the guidance of Xi Jinping’s important expositions on coordinated regional development for a new era, a series of achievements have been made in the field of coordinated development on a provincial and national level. The development ideas embodied will provide China’s solutions and experience for global coordinated regional development and the common progress of humanity.