Abstract: Coordinated development is a major concern in the national strategy of the Yangtze River Economic Belt (YREB). However, there are few studies which have quantitatively measured the level of coordinated development in the YREB. This paper aims to propose an comprehensive index of coordinated development based on the theories of growth pole and complex ecosystem and new guidelines of development from the central government. The index is composed by 18 indicators within 4 domains including economic development, technology & innovation, communication & transportation, and ecological protection. The scores of coordinated development capability of the 110 prefecture-level cities in the YREB are calculated and examined using natural break point analysis, spatial autocorrelation analysis and rank-size analysis. It is shown that Shanghai, Nanjing and Wuhan are leading the coordinated development in the YREB. Generally, the scores of coordinated development capability are higher in the eastern region of the YREB, in which the cities perform well in the domains of economic development, technology & innovation and communication & transportation yet show poor performance in ecological protection. Most cities in the middle reach of Yangtze river rank in the middle in the YREB in all the domains, except the provincial capitals. The western region of the YREB gets the lowest score in the coordinated development capability besides the largest cities such as Chongqing, Chengdu, Kunming and Guiyang. The correlation coefficients between ecological protection and other domains are〖JP〗 very low, suggesting that few cities have achieved a win-win situation between environment protection and socio-economic development. We suggest three ways to promote coordinated development in the YREB: establishing multi-level institutional designs; enhancing the innovation in green industries; and strengthening the joint prevention and control of ecological risks.