Germination is well-known to enhance the digestibility, functionality, and palatability of plant seeds. To examine the functionality of germinated-safflower seed (GSS), proliferative and differentiative effects of GSS extract on the mouse calvarial bone cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolinbromide (MTT) assay and alkaline phosphatase activity, respectively. Water extract of GSS increased dose-dependently proliferative and differentiative effects on calvarial bone cell, and its effects were stronger than those of ungerminated-safflower seeds (UGSS) extract. One major component was isolated from GSS extract by a series of purification procedure of solvent fractionation, Diaion HP-20, and Sephadex LH-20 column chromatographies. Its chemical structure was identified as trachelogenin (TC) by nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectral analysis. Trachelogenin showed significant proliferative (125.7%) and differentiative (132.1%) effects on calvarial bone cells at $10^{-8}M$, and its effects were significantly higher than those of $17{eta}-estradiol;(E_2)$. TC was found to be a major active compound responsible for high proliferative and differentative effects of the water extract of GSS. Therefore, these results suggest that TC in GSS may be useful as potential therapeutic agent for the prevention and treatment of bone loss.