In this study, the phenolic compounds of melon root exudates were identified by HPLC and seven phenolic compounds including gallic acid, phthalic acid, syringic acid, salicylic acid, ferulic acid, benzoic acid and cinnamic acid were observed. The laboratory experiment showed that ferulic acid, benzoic acid and cinnamic acid of 0.1 and 0.25 mmol·L^-1 could significantly promote the germination of Fusarium oxysporum f. sp. melonis spore while salicylic acid inhibited the spore germination to some degree. Syringic acid and ferulic acid significantly promoted the mycelium growth at the late stage of incubation. The pot experiments demonstrated that cinnamic acid, benzoic acid and ferulic acid enhanced melon infection at concentrations of 0.05, 0.1 and 0.5 mmol·L^-1.