An approach mainly based on thermogravimetric analysis (TGA) was developed to evaluate the stoichiometric ratio (SR, guest to host) of the guest-alpha-cyclodextrin (Guest-alpha-CD) inclusion complexes (4-cresol-alpha-CD, benzyl alcohol-alpha-CD, ferrocene-alpha-CD and decanoic acid-alpha-CD). The present data obtained from Fourier transform-infrared (FT-IR) spectroscopy showed that all the alpha-CD-based inclusion complexes were successfully prepared in a solid-state form. The stoichiometric ratios of alpha-CD to the relative guests (4-cresol, benzyl alcohol, ferrocene and decanoic acid) determined by the developed method were 1:1,1:2,2:1 and 1:2, respectively. These SR data were well demonstrated by the previously reported X-ray diffraction (XRD) method and the NMR confirmatory experiments, except the SR of decanoic acid with a larger size and longer chain was not consistent. It is, therefore, suggested that the TGA-based method is applicable to follow the stoichiometric ratio of the polycrystalline alpha-CD-based inclusion complexes with smaller and shorter chain guests. (C) 2012 Elsevier B.V. All rights reserved.