Abstract: This article calculates and compares synthetical strength of the 15 cities in the Changjiang River Delta through principle component analysis by setting up a series of indexes, including 5 stratums, 16 aspects, 34 indexes total. On the analysis, by normalizing the indexes with Statistical Software SPSS10.0, rotating them by the method of varimax, analyzing the component matrix, six components were draw. And then, by multiplying each component score and orresponding component proportion, summing the consequences, the synthetical strength of the cities was calculatecd. From high to slow, they are Shanghai, Nanjing, Hangzhou, Suzhou, Wuxi, Ningbo, Zhenjiang, Shaoxing, Changzhou, Nantong, Yangzhou, Taizhou,Zhoushan, Jiaxing and Huzhou. According to the level of the synthetical strength, the cities were classifies into one core and three circles. In the development of the future, Shanghai should be put in a central position in the Changjiang River Delta and Nanjing, Hangzhou, Suzhou in important pivot positions, and regional divisio n to enhance common prosperity and collaboration be strengthend.

Key words: the Changjiang River Delta, city, principle component analytical, synthetical strength