Phytochemical constituents were isolated from the aerial parts of Taraxacum coreanum (Asteraceae) by repeated column chromatography and prep-HPLC. Their structures were identified as ${eta}$-sitosterol (1), daucosterol (2), taraxasteryl acetate (3), chrysoeriol (4), diosmetin (5), luteolin (6), luteolin-7-O-glucoside (7), esculetin (8), and 5-hydroxypyrrolidin-2-one (9) by the interpretation of spectroscopic analyses including MS, $^1H$-, and $^{13}C$-NMR. This is the first report on the isolation of compounds 1-9 from T. coreanum. Among the compounds, 5 and 9 were isolated for the first time from Taraxacum.