Leaves of Nicotiana glutinosa were treated with ether vapor (0.025-0.05 %) for various hours after inoculation with tobacco mosaic virus. Local lesion number on the leaves was significan t ly decreased by ether narcotization when treated for three or five hours immediately after inoculation. Local lesion number was significantly decreased by twenty four h o urs ether treatment started within two hours after inoculation of TMV. One hour narcotization which began two hours after inoculation promoted the production of local lesions. It was concluded tha t the production of local lesions on N. glutinosa by TMV was inhibited by ether narcotization of the leaves for more than three hours, starting to treat within two hours after inoculation of TMV. Some considerations on the mechanism of the inhibition of lesion production of the ether treated plants were given.