Twenty-nine specimens of the infected plans were collected from areas through the country since 1967 to 1968. We report here four unrecorded causla organisms of powdery and their hosts which were identified in this work. The results as as follows : 1. Microsphaera diffusa Cooke et Peck (M.magnoliae Sawoda) (Host:Magnolia obovata Thunb.) 2. Sphaerotheca humili (de Condolle0Burill. (Host: Spirea sp.) 3. Phyllactinea fraxini (de Condolle)Homma. (Host : Betuls sp.) 4. Uncinula sengorui.Salmon.(Host : Celastrus orbiculatus, Thunb.) * Six unrecorded host 1. Altemisia japonica. Thunb. (Pathogen : Erysiohe cichoracearum DC.) 2. Aster tataricus. L. (Pathogen :Sohaerotheca fuliginea (Schlechtendahl) Poll. 3. Dohlia variabilis Defont. (Pathogen :Sphaerotheeca fuliginea (schlechtendahl) poll. 5. Helianthus ammues (Pathogen :Spherotheca fuliginea schlechtendahl) poll. 6. Solanum melangera L. (Pathogen : Erysiphe cichoracearum DC.)