The surface chemistry of catalyst plays a vital role in the catalytic process. And the effects of surface groups of porous boron nitride (p-BN) on the hydrogenation reaction have not been studied in detailed. In this work, two main surface species of Co/p-BN catalyst were tuned thermally and their roles on the hydrogenation reaction were discriminated by alpha, beta-unsaturated aldehyde hydrogenation reaction. The surface B-O content decreased at higher reduction temperature and the cobalt phase changed from CoO to the mixture of CoO and CoO. The Co/pBN-500 exhibited the highest selectivity to C=O hydrogenation. And its turnover frequency (TOF) of 13.2 h(-1) is close to the optimal value of reported cobalt catalysts. When the reaction proceeds, hydrogenation rate of C=O increases but that of C=C decreases gradually, thus a surface groups variation was expected at the initial period. Further in-situ FTIR spectra showed the band intensity of edge N-H increases as the adsorption proceeds at 50 degrees C but it decreases as the temperature rise to 200 degrees C, in combined with the shift of C=O adsorption peak, a intermolecular hydrogen bond between edge N-H and the terminal C=O group was suggested, which account for the better selectivity to C=O than C=C.