The supported nickel phosphate precursors were prepared by incipient wetness impregnation using nickel nitrate as nickel source, diammonium hydrogen phosphate as phosphorus source, and MCM-41, MCM-48, SBA-15 and SBA-16 as supports, respectively. Then, the supported Ni2P catalysts were prepared by temperature-programmed reduction in flowing H2 from their nickel phosphate precursors. The in situ diffuse reflectance FTIR spectroscopy (DRIFTS)analysis with the probe molecule CO was carried out to characterize the surface properties. The results indicated that there were significant differences in the spectral features of the samples. The νCO absorbances observed for adsorbed CO on mesoporous molecule sieve was attributed to weak physical adsorption. There are four different kinds of νCO absorbances observed for adsorbed CO on Ni2P/MCM-41 catalyst with the following assignments: (1)the formation of Ni(CO)4 at 2 055 cm-1. (2)CO terminally bonded to cus Niδ+(0<δ<1)sites at 2 091 cm-1. (3)CO terminally bonded to Ni+ sites at 2 127 cm-1. (4) CO terminally bonded to P and form PCO between 2 198 and 2 202 cm-1. There are two different kinds of νCO absorbances observed for adsorbed CO on Ni2P/MCM-48, Ni2P/SBA-15 and Ni2P/SBA-16 catalysts. The absorbance observed at 2 051-2 055 cm-1 for CO adsorption on Ni2P/MCM-48, Ni2P/SBA-15 and Ni2P/SBA-16 catalysts is due to the formation of Ni(CO)4 species. The other νCO absorbances observed at 2 093-2 096 cm-1 was attributed to CO terminally bonded to cus Niδ+(0<δ<1)sites.