Abstract: Antimicrobial activities and chemical compositions of water extracts of ethyl acetate extracts of Dictyophora indusia fisscher and Dictyophora echinovolvata were studied. The filtering paper method was applied to the antimicrobial activity test. The chemical compositions of the extracts had been researched by Gas Chromatography-Mass Spectrometry (GC-MS) . The results showed that the extract of Dictyophora indusia fisscher had strong antimicrobial effects on bacteria but weak on yeast and mold. The extract of Dictyophora echinovolvata had strong antimicrobial activity to mold, yeast and bacteria tested. Meanwhile, the antimicrobial activities under high temperature and strong pressure were stable. GC-MS analysis indicated that the major compositions of the extracts were fatty acids, olefins, phthalates, phenols and ketones.