Abstract: The anti-fungal activity of zicao of Fulvia fulva (Cooke) Cifferri in vitro and the control effect on tomato leaf mold in vitro were reported. A.euchroma pigment was extracted by petroleum ether from A.euchroma plants. Using the method of germination on the plate surface and the growth speed of the colony, the anti-fungal activity of the pigment was tested. Results showed strong inhibition on the spore germination, germ length and the hypha growth of the pathogen. The EC50 were 17.4, 1.0 and 200.4 μg/mL respectively. And it also showed 90.5% control effect on tomato leaf mold in vitro when the concentration was 800 μg/mL.