Abstract: Based on the resistant and susceptible reaction in watermelon varieties, Sugar Baby、Charleston Gray and Calhoun Gray, which is susceptible, moderate and resistant, respectively. 46 isolates from watermelon-growing areas were classified into 3 races like race 0, race 1 and race 2 which were 8 (17.4), 30 (65.2), and 8 (17.4%), respectively. Pathogenecity of race 0 isolates are weakest which only make Sugar Baby susceptible; isolates of race 1 are intermediately pathogenetic, they make Sugar Baby and Charleston susceptible Gray but Calhoun Gray resistant; isolates belonging to race 2 possess the strongest pathogenecity, which make 3 hosts susceptible. Isolates of race 0 mainly distribute over the central and southern Hebei province, whereas race 2 cover the middle and north of Hebei, isolates of race 1 exist in the whole watermelon-growing areas in Hebei province.