The adsorption of CO at low temperatures (130-293 K) has been investigated on Rh/Al2O3 catalysts of low (0.001-1 wt%) Rh loadings by means of Fourier transform infrared spectroscopy. The surface structure of Rh produced at different reduction temperatures (573 and 1173 K) was shock-cooled to 130 K, where the addition of CO caused the appearance of the band due to bridge-bonded CO ((Rh-0)(2)-CO) on all samples. The appearance of the bands due to gem-dicarbonyl (Rh+(CO)(2)) and linearly bonded CO (Rh-x-CO) depended on the Rh content and the reduction temperature of the catalysts. The positions and the integrated absorbances of the symmetric and asymmetric stretchings of the Rh+(CO)(2) changed with temperature. On the basis of the above findings the rearrangement of the adsorbed CO species (indirectly that of surface Rh) is discussed.