Abstract: The influence of Colletotrichum capsici f. nicotianae toxin on cell membrane permeability and chlorophyll content of tobacco was experimented in 2002.The results showed that the cell membrane permeability of tobacco could be increased by toxin inoculating, however, the influences were different among tobacco cultivars with different resistance to Colletotrichum capsici f. nicotianae.The content of chlorophyll was reduced to some extent 36-60h after toxin inoculating.