The carbon dioxide reforming of methane over the reduced supported Rh (0.5wt.%) catalysts was investigated. Two kinds of oxides, reducible (CeO 2 , Nb 2 O 5 , Ta 2 O 5 , TiO 2 , and ZrO 2 ) and irreducible (γ-Al 2 O 3 , La 2 O 3 , MgO, SiO 2 , and Y 2 O 3 ) were used as supports. Among the irreducible metal oxides, γ-Al 2 O 3 , La 2 O 3 and MgO provided stable catalytic activities during the period of study, and the activity increased in the sequence: La 2 O 3 <MgO~γ-Al 2 O 3 . Deactivation, however, occurred over the SiO 2 and Y 2 O 3 supported catalysts. Possible explanations for stability, based on the strong interactions between Rh 2 O 3 and support, were proposed on the basis of TPR and XRD studies. Among the reducible oxides, Nb 2 O 5 provided a low activity, ZrO 2 and CeO 2 exhibited a very long activation period, and deactivation occurred over Ta 2 O 5 and TiO 2 . Most of the reducible oxides provided much lower yields to CO and H 2 than the irreducible ones, and they are not suitable supports for Rh in the CO 2 reforming of methane. In summary, MgO and γ-Al 2 O 3 are the most promising supports; they provided a stable high activity with a CO yield of 83-85% and a H 2 yield of 76-79% at the high space velocity of 60000ml/h/g.