Abstract: Based on the relevant data of 41 cities in the Yangtze River Delta City Group from 2016 to 2021， the study uses the entropy-weighting TOPSIS method to build a high quality development comprehensive assessment system. The system includes 20 indicators from the five aspects of innovation，coordination，green，opening up，and sharing. It can test a city’shigh quality development level as well as the evolutionary tendency of its subsystems’coupling coordination. The results show that the high quality development level of the Yangtze River Delta City Group continues to improve，and the difference is mainly reflected in the innovative and open development levels； cities of the lowest innovative and open development indexes are mainly located in the northern regions of Anhui and Jiangsu Provinces；differences of the fluctuation degree of the city cluster’shigh quality development are great，with some cities in southern Jiangsu，eastern Zhejiang，and southern Anhui having stronger development resilience and durability；and the coupling coordination degree of the city cluster’ssubsystems is low. Hence，innovation should be held as the dynamic engine to enhance the sci-tech cooperation capacity of the central cities in the city group；the path and form of opening up should be improved to build a more open business climate and a freer trade pattern；great importance should be attached to the policies and measures for coordinated development，so as to promote the sharing and green life style and bring about changes to people’slivelihood.

Key words: the Yangtze River Delta City Group；high quality development；coupling coordination； entropy-weighting TOPSIS method