Abstract: Eco-civilization construction is a task of paramount importance for the sustainable development of the Chinese nation. The State proposes to build the Yangtze River Economic Belt into a pioneering demonstration zone in ecological civilization construction in 2014. To explore “Two Mountains” development patterns and realization paths of eco-civilization in Yangtze River Economic Belt in depth, this study proposed four “Two Mountains” development patterns including “harmonious coexistence”, “green poverty”, “antagonistic development” and “golden pollution” based on the socio-economic development and eco-environmental performance of cities used eco-civilization data of 2015 and 2019. According to the findings: (1) Cities under “harmonious coexistence” and “green poverty” patterns account for the highest proportion. The proportion of cities under the “harmonious coexistence” pattern increases constantly, while that of cities under the “antagonistic development” pattern reduces Significantly. (2) From the perspective of industrial development path, all-round balanced development offers the most effective path to realizing eco-civilization in Yangtze River Economic Belt. The green innovation driving type, green transformation and upgrading type and ecological value realization type paths exerted similar effects in driving the harmonious coexistence of eco-civilization. This study analyzes the “Two Mountains” patterns and paths of Yangtze River Economic Belt’ eco-civilization at prefecture-level, would provide experience and reference for the green and sustainable development of areas with different natural endowments in China.