Yangzi river urban agglomeration, as a vital place situated in the down-stream of Yangzi river economic zone, is a leading engine of "1+3" key functioning area in Jiangsu province. Green ecological construction of Yangzi river urban agglomeration is of strategic sense for constructing new Jiangsu and protecting Yangzi river. This paper studies the decoupling level and driving factors of industrial energy carbon emission of Yangzi river urban agglomeration. Its industrial carbon emission generally shows an increasingly fluctuating trend, with Nanjing and Suzhou much larger than other cities. The decoupling has roughly undergone expanding linkage, strongly decoupling and weakly decoupling, overall a rising decoupling level, unstable, varying largely with urban agglomeration, but in process of optimization. Factors such as carbon emission intensity effect and energy intensity effect promote the decoupling level, but offset by industrial economy size, regional economy proportion and energy structure. This paper presents suggestions on boosting tentative construction of low carbon city, establishing whole domain carbon exchange market, optimizing energy structure and stimulating scientific innovation, in order to promote a quality development of Yangzi river urban agglomeration.