Abstract: The extraction of antifungal substance from the corm of Gladiolus hybridus was experimented and its antifungal vitality was tested by sampling Trichoderma sp. on medium mixed with the purified polyose substance through extraction, isolation and selection, and culturing on a certain kind of medium. The antimycotic spectrum of the purified bio-substance with large molecular weight was determined with several fungi species that often cause dermatomycosis of human beings. The result showed that the antifungal vitality of the polyose bio-substance extracted and purified from G. hybridus corm was strong with broad antimycotic spectrum.