Several calcium titanate samples were prepared by a flux method with various flux salts and various substrate concentration and also by a solid state reaction method. The prepared calcium titanate of various morphologies were loaded with Ag cocatalyst, and examined for the photocatalytic reduction of carbon dioxide with water. A sample prepared with a NaCl flux with a moderate concentration of solute exhibited the highest and stable photocatalytic activity for carbon monoxide production among the prepared samples. It is revealed that the large and flat facets could stabilize the Ag cocatalyst nanoparticles on the surface to enhance the photocatalytic activity for the carbon monoxide production.