In this study, we screened the presence of mycoviruses from a collection of 60 Magnaporthe oryzae (M. oryzae) strains using the cellulose chromatography method and found that 14 strains harbored dsRNAs. A virus–curing derivative strain GD45–4 was obtained from the dsRNA–infecting strain GD45 by high temperature–ribavirin combined virus–curing methods. When compared to the original strain GD–45, strain GD45–4 showed a more full and straight hypha, and a whiter and fluffier colony morphology on PDA, indicating the elimination of dsRNAs affected the phenotype of strain GD45.