For investigation of the species diversity of the Genus Crepidotus in Korea and constructing a key to Korean Crepidotus species, a total of 65 specimens, collected from 18 locations from 1982 to 2002, were observed for morphological characters of carpophores and other features. All the specimens have been preserved in the herbarium of the National Institute of Agricultural Sciences and Technology, R.D.A., Suwon, Korea. The specimens were identified according to the classification systems given by Hesler and Smith(1965), Nordstein(1990), Orton(1960), Pilat(1948), Senn-Irlet(1991, 1992, 1993) and Singer(1951, 1973, 1986). In this study, a total of 10 Crepidotus species were confirmed. Among them, Korean common names were designated to six unrecorded species as follows: C. uber, "끈적귀버섯"; C. hygrophanus, "곤약귀버섯"; C. latifolius, "꼬마무리귀버섯"; C. obscurus, "먼지귀버섯"; C. subverrucisporus, "분홍주름귀버섯"; and C. circinatus, "노란고리귀버섯". A key to 10 Crepidotus species has been constructed.