Nitrogen adsorption and high-resolution thermogravimetry were used to study a series of samples prepared by coating Porous silica with different amounts of siloxane polymer. Thermogravimetry was employed to investigate the thermal behavior of the coated samples as well as the polymer-silica interactions. Nitrogen adsorption was used to monitor the changes in the specific surface area, porosity, and surface properties upon polymer coating. It is shown that the gradual changes in the aforementioned properties are observed up to some limiting coating level. Also, in this coating range a rather uniform film is formed by siloxane polymer on the silica surface.