The inclusion complexation behavior, characterization and binding ability of crassicauline A (CLA) with beta-cyclodextrin (beta-CD) has been investigated in both solution and the solid state by means of UV-vis spectroscopy, FT-IR, (1)H and 2D NMR, XRD, SEM and DSC. The results showed that the water solubility and thermal stability of CLA were obviously increased in the inclusion complex with beta-CD. This satisfactory water solubility and high stability of the CLA/beta-CD complex will be potentially useful for its application as herbal medicine or healthcare products. (C) 2011 Elsevier Ltd. All rights reserved.