The present study aims to investigate the lignan constituents from Sambucus williamsii and their proliferation effects on osteoblast-like UMR106 cells. Seven compounds were isolated and purified by macroporous resin D101, silica gel, Sephadex LH-20, Toyopearl HW-40, ODS column chromatographies and Preparative HPLC(C-18). Their structures were elucidated by spectroscopic methods as threo-guaiacylglycerol-beta-0-4'-conifery ether (1), lirioresinol A (2), 1-hydroxypinoresinol (3), 5-methoxybalanophonin (4), balanophonin (5), 5-methoxy-trans-dihydrodehydrodiconiferyl alcohol (6), and p-hydroxybenzaldehyde (7). Compounds 3-7 were obtained from this genus for the first time. The proliferation effects of all isolated compounds on osteoblast-like UMR106 cells were determined. Compounds 1-7 (1 x 10(-12)-1 x 10(-7) mol x L(-1)) increased UMR106 cell proliferation to some extent.