Abstract: The structure of hainanolidol, a neutral constituent isolated from Cephalotaxus hainanensis Li, was confirmed by treatment with lead tetraacetate which gaye a product with IR and MS spectra identical to hainanolide, the structure of which has already been elucidated by X-ray crystallography. The result of the stereospecific reaction of hainanolidol with α-butyric anhydride favored the R-configuration of C₁₄. Since both hainanolide and hainanolidol showed positive cotton effect curries, the absolute configurations of the two compounds, should be interrelated as shown in formulas Ⅰ and Ⅱ.