Abstract: The fungicidal activity of 10 compound containing N-(2-trifluoromethyl-4-chlorophenyl)-2-oxo and 2-hydroxycycloalkylsulfonamides against 14 fungus species were evaluated by the method of mycelial growth inhibition.The results of bioassay at concentration of 50 mg/L showed that compound A3,A4,B3 and B4 possessed a broad anti-fungal spectrum,which was similar to or broader than those of chlorothalonil.The EC50 values of compound A3 and B3 against Gibberella zeae (Schw.) Petch,Verticillium dahliae,Sclerotinia sclerotiorum (Lib.) de Bary,Fusarium moniliforme Sheld,Bipolaris sorokiniana (Sacc.) Shoem,Curvularia lunata (Walker) Boed,Colletotrichum gossypii Southw and Corynespora cassiicola were all less than 20 mg/L.The fungicidal activity of 2-hydroxycycloalkylsulfonamides against fungi was similar to that of 2-oxocycloalkylsulfonamides,and compounds containing 7 or 8-membered ring were better than those containing 5,6 or 12-membered ring.