RhCl(CO)(PPh₃)₂, and [RhCl(CO)₃]₃ were supported on silica gel, -alumina, titania, and magensia in 3 to 5wt% to study the interactions of rhodium carbonyl with the surface of inorganic oxides. When trans-RhCl(CO)(PPh₃)₂ was supported on the surface of silica gel, cis-RhCl(CO)(PPh₃)₂ species was detected via the splitting of the CO infra red stretching band of trans-RhCl(CO)(PPh₃)₂. With other supports, same phenomenon was observed but with the different pattern of intensities of the splitted CO stretching bands. RhH(CO)(PPh₃)₃ was easily decarbonylated, after interacting with the surface of silica gel, -alumina, and titania. However, [RhCl(CO)₂]₂ was decarbonylated on the surface of inorganic oxides mentioned above and most of supported [RhCl(CO₂)₂] converted to a stable surface carbonyl species [M-OH-RhCl(CO)₂ ; M=Si, Al, Ti]. Diffuse reflectance infrared spectroscopy(DRS)was used to study the interactions of 5 wt % RhCl(CO)(PPh₃)₂ supported on silica gel with H₂, CO and/or propylene at various temperatures. The result indicated that the surface intermediates formed from the interaction of RhCl(CO)(PPh₃)₂ with CO, H₂ and C₃H₆ were not identical to the corresponding liquid-phase intermediates of RhCl(CO)(PPh₃)₂ in the presence of solvent.