Abstract: After the trunk of Dracaena cochinchinensis was separately inoculated with Fusarium graminum var. dracaena, F. graminum var. yunnanensis and Cladosporium carpophilum for 5～15 days, small red circles emerged around its inoculated positions and gradually enlarged with increasing days, and the redness also gradually became deep. Antifungal experiment and HPLC analysis confirmed that 7,4'-dihydroxyflavan, 7-hydroxy-4'-methoxyflavan and Loureirin Awere the three phytoalexins which were extracted and identified from the red xylems.

Key words: Dragon's blood resm, Dracena cochinchinensis, Phytoalexins