A new diarylheptanoid, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-6-Oacetylglucoside (1), together with two known diarylheptanoids, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-glucopyranoside (2) and hirsutanonol (3), were isolated from Saxifraga tangutica. The structures of 1-3 were elucidated using 1D and 2D NMR spectral data, including high-resolution mass spectra (HR-ESI-MS). It was found that the new compound was acetyl-substituted (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-glucopyranoside.