Melampyrum roseum Max. is an annual herb in Scrophulariaceae plants. The materials were collected in Kyeongi-Do in 1980. The BuOH extract was evaporated under reduced pressure. The residue was column chromatographed over silica gel with benzene-MeOH (8 : 1) as an eluent and it gave the amorphus powder. Compound I has a molecular formula $C_{17}H_{26}O_{10}$ and it was identified as mussaenoside by chemical data, UV, IR, NMR spectra and compared with the authentic sample of mussaenoside tetraacetate.