Abstract: Specimens taken from skin lesion of 5 cases clinically identified patients with sporotrichosis were studied by electron microscopy, The ultrast-ructural characteristics of sporothrix schenckii in the skin lesion and on culture medium, and the composition of the cells in the granulomatous linflammation caused by sporothrix schenckii were presented and discussed.The cultured fungirevealed a fine ultrastructore, but the fungi in skin lesions on electron microscopy showed many ultrastructural changes and degeneration, These changes and degeneration were probablp related with the resistance of, host cells to the fungi. The authors suggest that electron-microscopic study is of great importance in elucidating biological properties of fungous cells.