LEE, Gu Young (Ghoong Pook College, Chungju, Korea)-Studies on the leaf spot of Yucca caused by Coniothyrium sp. Kor. Jour. Bot., 4(1)2l~24‥1961.-The strains of fungus which belong to Coniothyrium genus were isolated from leaf spot of Yucca. The isolated strain can grow easily and forms characteristic colonies on Saido`s soy agar. There are definite differences, according to other authors,(By Miyake et Hara 1911) Pycnidio-spore are usually formfd ellipsoidal, dark brown, 4 x 2. 5-4. Oμ in size, whereas isolated strains are globose, yellowish brown, 2.8-4.2μ in diameter. The positive inoculation test can be attained by burned petridish method, preserving it in incubator at 28℃, and the pycnidio-spore can be reisolated from the inoculated portion. (Photo.7) Up to the present day there is no report for leaf spot of Yucca caused by Coniothyrium sp. Comparing the writer`s isolate with those fungi described (leaf spot of alloe, rose canker and elm canker etc.) hitherto, there are no accordance in the symptom and especially in morphological characters and Pathogenicitys.