Taking the relevant data in 13 prefecture-level cities of Jiangsu province from 2002 to 2013, this paper makes an analysis on the relationship between regional economic concentration and regional financial stability. This result shows that there is a correlation between them: regional economic concentration is the Granger causality to regional financial stability. Owing to a positive impulse from regional economic concentration, regional financial stability will change after the first negative. With the increase of regional economic concentration, regional financial stability presents the U-type change: “first fall and then rise”.