For the investigation of medicinal resources from Taraxacum species, the studies were carried out to evaluate the pharmaco-constituents in the aerial part of Taroxacum hallaisanensis, an endemic plant of Korea. From BuOH fraction of the MeOH extract, compound 1 (protocatechuic acid, $C_7H_6O_4,;3,4-dihydroxy;benzoic;acid)$, compound 2 $[C_{22}H_{31}O_6,;luteolin-7-O-{alpha}-_L-rhamnopyranosyl(1{ ightarrow}6)-{eta}-_D-glucopyranoside]$, and compound 3 $[C_{15}H_{20}O_6,;luteolin-7-O-{eta}-_D-glucopyranoside]$ were isolated by column chromatographic separation using polyamide and ODS-gel. The structures were elucidated by means of physico-chemical evidences($^1H-NMR,;{12}^C-NMR$, IR, EI-Mass, FAB-Mass and GC).