The anti-microbial activities of petroleum ether,ethyl acetate and ethanol extracts from Cichorium intybus L.roots to seven pathogenic fungi and three pathogenic bacteria were in vitro measured and the performances of the extracts from Cichorium intybus L.roots in preventing and controlling wheat powdery mildew were investigated through pot experiment.The results showed that ethyl acetate and ethanol extracts presented certain inhibitory effects on the pathogenic fungi and bacteria and ethyl acetate extract...