The solubility of carbaryl increased with increasing concentrations ofβ-CD, G2-β-CD, and M-β-CD. The result suggests theformation of soluble inclusion complex. Solubility increase was highestin M-β-CD-carbaryl, being 18.4 fold higher than that of carbaryl when 100 mM M-β-CD was used. The apparent formation constant for the complex calculated from phase solubility diagram was 223.18 M-1. The preparation of the complex in solid form for characterization was successful by kneading andfreeze-drying. The DSC curves for kneading and freeze-drying mixture didnot show the endothermic peak characteristic of carbaryl, but a small new endothermic peak was observed. FTIR analysis showed a shift of the major peak of carbonyl group in carbaryl molecule from 1717 to 1744 and 1734 cm-1 in kneading and freeze-dried mixtures, respectively. M-β-CD-carbaryl complex demonstrated higher dissolution rate, higher thermal and UV stability but lower toxicity than its parent carbaryl compound.