Concentration of silanol groups on silica gel surface has been quantitatively determined using the deuterium exchange method. Simple and effective procedures have been used in pre-sample drying, deuterium exchange and extraction of resulting isotopic mixture from the exchange reaction. Each of four silica gel samples with varying surface area has been subjected to pre-drying to remove adsorbed water and then quantitatively mixed with deuterium oxide in a steel bomb for isotopic exchange. The resulting D₂O/water mixture was then extracted by applying high pressure using infrared pellet press. The infrared spectrum of the isotopic mixture was measured and the composition was then determined by a multivariate calibration model established between infrared profiles of water in D₂O standard mixtures and their composition. The results show that the silanol group concentration determined agrees with the values reported in the literature.