Cyazofamid is a kind of sulfaimidazole fungicide. It has high biological activity against oomycetes such as Phytophthora, frost mold, pseudofrost mold, Pythium and Brassica Rhizopus. Suitable crops are potatoes, grapes and vegetables (cucumber, cabbage, tomato, onion and lettuce). The control objects are downy mildew and epidemic diseases, such as cucumber downy mildew, grape downy mildew, tomato late blight, potato late blight, etc.