A new lignan bombasinol A (1), together with three known compounds was obtained from the ethanol (95%) extract of roots of Bombax ceiba L. through its being subjected to silica gel and Sephadex LH-20 chromatography. Their structures were elucidated as 4-(4-(3,5-dimethoxyphenyl)hexahydrofuro[3,4-c]furan-1-yl)-2-methoxy-phenol (1), 5,6-dihydroxymatairesinol (2), (+)-pinoresinol (3) and matairesinol (4) on the basis of spectroscopic methods, including 1-D and 2-D NMR (HSQC and HMBC) experiments and by comparison of the data with those previously reported literatures. All these compounds were the first reported from Bombacaceae. The anti-Hepatitis B Virus (HBV) activity of all compounds isolated from B. ceiba in the research was evaluated. From the results of the HBV assay, these tested compounds showed inhibitory activity against HepG2 2.2.15 cell lines. Compounds 1-4 showed relative differences in their abilities to inhibit HBsAg secretion, with IC50 values of 118.3, 123.7, 118.9 and 218.2 mM, respectively.