OBJECTIVE To investagate the stability of vitamine D3 in beta-cyclodextrin. METHODS The concentration of vitamine D3 was determined by HPLC,the degradation produc ts were detected with thin-layer chromatography. RESULTS Compared with drug substance D3 in the inclusion was more stable. CONCLUSIONS This is a efficient method to prepare the D3-β-CD for enhancing the stabili ty of vatimine D3.