Abstract: Taking diallyl disulfide（DADS）and Fusarium oxysporum（FO）of cucumber as test materials,and PDA culture of FO and radicle inoculation methods were used,the effects of DADS on the hypha growth of FO and the pathogenesis of cucumber wilt disease were studied,in order to confirm the inhibitory effect of DADS on cucumber wilt disease.The results showed that DADS could inhibit the spore and mycelial growth of Fusarium oxysporum and its inhibitory effects was more significant with the increase of DADS concentratios;compared with the FO treatment,DADS+FO treatment could not only reduce the incidence of Fusarium wilt by 46.40% and the disease index by71.21%,could but also increase the fresh weight of root by 31.07% and the top fresh weight by5.24%;DADS treatment of cucumber seedlings could decrease peroxidase（POD）,catalase（CAT）activities,malondialdehyd（MDA）content,while,increase superoxide dismutase（SOD）activity as compared to Fusariumtreatment.