[Objective]The paper was to explore application of nativo in control against cucumber powdery mildew.[Method]Taking “Zhenghuang 3” cucumber as the material,the effects of nativo on growth of cucumber at different periods were studied by soaking seeds and spraying treatment on stems and leaves.The field efficacy trial against powdery mildew was also carried out to comprehensively evaluate control effect of nativo against powdery mildew.[Result]Seed soaking by nativo had good preventive effect on powdery mildew,while plant height,root length and increase rate of stem diameter were significantly lower than that of hexaconazole.Rates of plant height inhibition were 15.62% and 4.65% at seedling and flowering stage after spraying 60mg/L of nativo,respectively, which were significantly lower than that of hexaconazole.The control efficacies of nativo were 73.82%-84.26% in field trial,which was as good as that of hexaconazole but higher than that of Topsin-M.[Conclusion]Nativo is safe to growth of cucumber,with good control effect on powdery mildew.It can be used as an alternative fungicide to control cucumber powdery. [Objective] The paper was to explore application of nativo in control against cucumber powdery mildew. [Method] Taking “Zhenghuang 3” cucumber as the material, the effects of nativo on growth of cucumber at different periods were studied by soaking seeds and spraying treatment on stems and leaves. The field efficacy trial against powdery mildew was also carried out to comprehensively evaluate control effect of nativo against powdery mildew. [Result] Seed soaking by nativo had good preventive effect on powdery mildew, while plant height, root length and increase rate of stem diameter were significantly lower than that of hexaconazole. Rates of plant height inhibition were 15.62% and 4.65% at seedling and flowering stage after spraying 60 mg / L of nativo, respectively, which were significantly lower than that of hexaconazole. control efficacies of nativo were 73.82% -84.26% in field trial, which was as good as that of hexaconazole but higher than that of Topsin-M. [Conclusion] Nativo is safe to grow th of cucumber, with good control effect on powdery mildew. It can be used as an alternative fungicide to control cucumber powdery.