Abstract: The phytotoxin producing conditions of Cercospora eupatorii were experimented with different media, culture durations, initial pH values of the media, shaking intensity and illumination conditions. The results showed that the optimal cultural conditions for producing phytotoxin were in PD medium with initial pH 7.0, natural day-night illumination alternation and with shaking culture for 8 d. 5 types of solvents with different polarities were tested for the phytotoxin extraction and then followed by bioassay, it was showed that the solvents with greater polarities, such as methyl could fully extract the toxins produced by Cercospora eupatorii.