The infection process of the anthracnose fungus Discula theae-sinensis in tea was investigated in detail by fluorescence microscopy. Leaves of the susceptible tea variety ‘Yabukita’ spray inoculated with the conidial suspension were collected sequentially and examined after fluorescence staining with fluorescein-conjugated wheat germ agglutinin. Conidia adhering to the trichomes germinated and formed very short germ tubes. Penetration hyphae grew from the germ tube tips into the cell walls of the trichomes, and formed infection hyphae by 12 h after inoculation. Hyphae that had invaded the mesophyll were confined to the small round spots that formed surrounding the infected trichomes. However, hyphae that had reached the veins extended through the phloem, causing necrosis of the neighboring mesophylls and eventually the formation of large necrotic lesions.