Antifungal activity of ChiCW and synergistic interactions between ChiCW with fungicides were investigated. Conidial germinations of phytopathogenic fungi, Alternaria brassicicola, Botrytis elliptica, and Colletotrichum gloeosporioides, were inhibited by ChiCW but A. longipes was not. In addition, ChiCW showed synergistic effect with fungicides Switch (cyprodinil+fludioxonil) and tebuconazole to inhibit fungal conidial germinations. The level of synergism of ChiCW with tebuconazole was higher than that with Switch. The results indicate that ChiCW may exhibit a higher level of synergism with fungicides that have a primary effect upon membranes.