The　effect　of　supports　(MSU-1,),　gamma-Al2O3,　AC　(activated　carbon),　and　MgO)　on　the　catalytic　activity　of　Cr-based　catalysts　was　investigated　for　the　dehydrogenation　of　isobutane　with　CO2.　The　catalytic　activity　was　in　the　order　of　CrO,IMSU-1　＞　CrOx/Al2O3　＞　CrOx/AC　＞　CrOx/MgO.　The　catalysts　were　characterized　by　N-2　adsorption-desorption,　X-ray　diffraction　(XRD),　X-ray　photoelectron　spectroscopy　(XPS),　and　temperature-programmed　desorption　(TPD).　The　XRD　results　indicate　that　the　active　species　of　Cr　are　dispersed　well　on　the　supports.　N-2　adsorption-desorption　shows　that　the　support　MSU-1　has　the　largest　surface　area　(804.2　m(2)/g),　which　results　in　excellent　dispersion　of　Cr　and　highest　activity.　The　XPS　results　reveal　that　Cr6+　is　one　of　the　active　centers.　The　results　of　NH3-TPD　indicate　that　catalyst　activity　is　proportional　to　the　amount　of　weak　acid　adsorption　sites.　As　a　result,　the　best　support　is　the　MSU-1　zeolite　owing　to　its　high　specific　area　and　a　large　amount　of　weak　acid　sites.　The　59.2%　conversion　of　isobutane　and　the　39.5%　yield　of　isobutene　are　achieved　on　the　CrOx/MSU-1　catalyst.