The present invention relates to an aqueous gas-converting catalyst composition comprising: an active component; a support; an inorganic binder; at least one accelerator selected from the group consisting of cobalt oxide, molybdenum oxide, nickel oxide, calcium oxide, barium oxide, strontium oxide, magnesium oxide, zirconium oxide, manganese oxide and barium titania; and at least one stabilizer selected from the group consisting of magnesium oxide, zirconium oxide, stabilized zirconia, and hydrotalcite. The catalyst according to the present invention can effectively capture and separate carbon dioxide due to the excellent physical properties thereof such as packing density and abrasion resistance, and high CO conversion. Also, according to the present invention, mass production is facilitated by applying a spraying technique, and overall costs are lowered because of high yield. Thus, the present invention can be applied as a low cost pre-combustion CO2 capturing technique to an integrated gasification combined cycle, fuel cells, coal liquefaction, compound production, and the like.