In April of 2002, the gray mold disease occurred severely on kalanchoe (Kalanch oe blossfeldiana) grown in a nursery in Daesan-myon, Changwon City, Korea. The lesions were started with water-soaked spot and the leaves discolored from the tip and became gray or dark and gradully expanded to whole leaf. The conidia and mycelia of pathogen appearedd on flower, flower stalk and stem. Conidia were gray, 1-celled, mostly ellipsoid or ovoid in shape and were 8~17 5~12 in size. Conidiophores were 13~34 in size. The sclerotia were formed abundantly on potato-dextrose agar. The optimum temperature for sclerotial formation was . Pathogenicity of the causal organism was proved on Kalanchoe blossfeldiana according to Koch,s postulate. The causal organism was identified as Botrytis cinerea based on mycological characteristics. This is the first report on gray mold of Kalanchoe(Kalanchoe blossfeldiana) caused by Botrytis cinerea in Korea.