Inclusion complexation of $alpha$-cyclodextrin($alpha$-CD), $eta$-cyclodextrin($eta$-CD) and tri-O-methyl-$eta$-cyclodextrin(tri-O-methyl-$eta$-CD) with chlorpamide(CPA) in aqueous solution and in the solid state were studied by the solubility method, spectroscopy (UV, IR), differential scanning calorimetry (DSC) and powder X-ray diffractometry, and all their molar ratios were found to be 1:1. The solid complexes of CPA with three kinds of cyclodextrins were prepared by a freezedrying method, and their dissolution behaviors were examined. As a result, the release of CPA from the inclusion complexes was significantly improved. The intrinsic dissolution rate of CPA in cyclodextrin inclusion complexes was about 51 times ($alpha$-CD inclusion complex) and 12 tmies ($eta$-CD inclusion complex) larger than that of intact CPA.