Abstract: 【Objective】 Occurrence of Ampelomyces -hyperparasites of Erysiphales infesting iandscapeplant and optimizing isolation method. 【Methods】 In 2020, white powdery mildew parasite infesting 18 landscape plant species in Shihezi area were investigated, the isolation method of Ampelomyces quisqualis on the collected samples was optimized, and the medium suitable for isolating Ampelomyces was selected. 【Results】 The presence of Ampelomyces was detected on 17.The higher number of the samples with mycoparasites was noted in the case of compositae (the incidence of parasitism by A.quisqualis was 40.92).The highest number of the samples with mycoparasites was noted in the case of Golovinomyces (43.59 of the samples).The isolation rate of the water agar filter pickingpycnidia (90%) method was significantly (P<0.01) higher than that of direct pickingpycnidia with needle (30%) and reduced the contamination.The Ampelomyces were all able to grow on six medium, Czapek, PDA, PSA and their added malt extracts respectively, with isolation rates above 90.0%.But there were significant differences in the growth rate on different media.The growth rate of the colonies was significantly(P<0.05) enhanced due to the addition of malt extract, where the modified PSA and Czapek medium were more favorable for the isolation of Ampelomyces. 【Conclusion】 The high participation of the Ampelomyces is noted in the powdery mildew of the study.The water agar filter pickingpycnidia +the modified PSA and Czapek medium adding malt extract is effective method to isolate Ampelomyces.