Abstract:According to cultural characteristics on potato dextrose agar (PDA), there were five different culture types (A to E) of Verticillium dahliae isolates from 84 counties of 12 provinces in China. Among them, Type B was the dominant group accounted for 72.9%, which produced abundant microslerotia on PDA. The isolates from Yangtze River region showed higher variation than those from Yellow River and those from Xinjiang varied slightly. Based on the results from the pathogenicity tests and ISSR fingerprint, 167 isolates were clustered into three groups which showed high, moderate and low virulence to cotton, respectively. There was a close corelation between virulence and the ISSR fingerprint. Isolates with moderate virulence were dominant in China. High virulent isolates mainly distributed in Hebei, Henan and Hubei, whereas low virulent isolates mainly distributed in Xinjiang and Jiangsu.