Eco-city is an essential form of sustainable urban development and represents the tendency of modern cities. The evaluation of eco-city provides the fundamental basis for the planning, construction and management of eco-city. With the rapid development of social and economic, the connotation and evaluation index system of eco-city also need to update with the times. Currently, China's economy has shifted from a rapid growth stage to a high-quality development stage. Urban is an essential platform of regional economic development, it will also enter the stage of high-quality development. The eco-city is highly compatible with the concept of high-quality development, it is necessary to integrate the high-quality development ideology in the eco-city evaluation, which is in line with the current urban transformation and development requirements of China. Therefore, on the basis of combing the evolution and connotation development of eco-city, we set up an eco-city evaluation system guided by the concept of high-quality development, and then taking the Yangtze River Delta Urban Agglomeration (YRDUA) as an example to carry out the ecological level evaluation study of urban. Thus, the characteristics of spatial-temporal variations of urban ecological level was evaluated and the main obstacle factors was revealed. Based on various statistical data of YRDUA in 2005, 2010 and 2015, 27 indicators for evaluating eco-city that reflects the requirements for high quality development ideology were constructed from three aspects, they are economic development, ecological environment protection and social civilization progress. The entropy-TOPSIS model then analyzed the ecological level of cities, and the major obstacle factors was measured through obstacle degree model. The results showed that: The ecological level of the YRDUA present a steady improvement trend, the urban ecological level spatial pattern of the YRDUA shows a "core-periphery" structure, and it experienced the evolution process of double-high value center in 2005, single-high value center in 2010 and multiple-high value center in 2015. The ecological level of Shanghai municipality, provincial capital cities and other economically-strong cities like Suzhou and Wuxi are significantly better than other cities. There is a significant correlation between ecological level and city hierarchical, which means the urban ecological level is directly proportional to the population scale. The higher the urban hierarchy, the more advantageous the urban construction has, thus the higher the ecological level is. And the ecological level gap of the different urban hierarchy has gradually expanded during the study period. From the perspective of the 3 subsystems, economic development, ecological environment protection and social civilization progress, each city presents different advantages and disadvantages regarding different indicators. Moreover, the difference of ecology level regarding the economy and society are significant than the ecological environment. The obstacle factors of the ecological level of the YRDUA are relatively stable. For most cities, economic development, infrastructure, and public service factors are the primary constraints, especially in cities with relatively backward economic development, while a few economically developed cities have significant obstacles to environmental foundation and social civilization progress. In the future, the differentiated policies deserve much more attention, urban ecological level should promote to higher quality according to local conditions especially its significant constraints.