Abstract: According to the panel data of 26 cities in the Yangtze River Delta urban agglomeration from 2005 to 2018,this paper uses factor analysis to evaluate the degree of financial agglomeration of cities over the years,and uses the financial openness index to conduct the K-means dynamic clustering division based on feature extraction,and empirically analyzes the impact of financial openness on the financial agglomeration of cities in the Yangtze River Delta.The results show that,on the whole,financial opening up has a significant positive impact on the degree of urban financial agglomeration,but this promoting effect is mainly concentrated in the developed cities with higher level of financial opening up,and shows a negative inhibitory effect in the less developed cities with lower level of opening up,which shows obvious heterogeneity among regions.

Key words: financial openness, financial agglomeration, factor analysis, feature extraction, cluster analysis