The combination of ethaboxam and transgenic plants provides enhanced plant protection in controlling plant disease. According to the present invention, an application of an effective amount of ethaboxam to transgenic plants applied to plant foliage parts; soil-applied in drench or soil incorporation; or applied to seed using seed slurry application, seed film coating and seed pelleting technologies for seed, gives a good controlling effect on plant diseases. Application of ethaboxam to transgenic plants encompasses all monocotyledonous and dicotyledonous crop types.