Impregnation method was used in this study to prepare five different Rh based catalysts supported on MCM-type mesoporous silica materials. These catalysts were evaluated based on their performance for the hydroformylation of dicyclopentadiene (DCPD) to produce diformyltricyclodecanes (DFTD). While a selectivity of DFTD was only 8.7% using monometallic Rh/MCM-41 as catalyst, the selectivity was enhanced to 76.2% at a similar DCPD conversion using bimetallic Co-Rh/MCM-41 catalyst, even when the Co loading was very low(25 mol% relative to Rh). Extensive catalyst characterization including TPR, TPD, XRD, XPS, BET and TEM was performed to study the nature of metal modification on Rh/MCM-41. It was found that modification on the Rh/MCM-41 by Co addition could substantially enhance the selectivity towards DFTD. This improvement was likely attributed to the formation of a more reactive Rh species on the catalyst surface.