Abstract：The pathogen of eggplant powdery mildew in Xichang district，Sichuan province was identified and the characteristics of conidial germination was studied．The results indicated that the conidial of pathogen causing eggplant powdery mildew in Xichang district was single birth．The top of the primary conidia was cuspate，（65.44-84.98）μm×（17.31-22.09）μm by size．The secondary one was cylindrical，（69.92-83.32）μm×（15.82-21.53）μm by size．Conidiophores were unbranched，with 2-4 cells and 102.59-179.50 μm in length．Chasmothecia was not observed．The pathogen was initially identified as Oidiopsis tropaeoli（Berger.）．Conidia germination characteristics study indicated that the optimum temperature for germination was 25 ℃，and the lethal temperature for conidia was 54 ℃．Conidia could germinate while the relative humidity was above 90%，but under 100% moisture condition the germination rate was the highest. Light had inhibitory effect on conidia germination.
