In situ interactions of trivinylethoxysilane (TVES) with oxidized surfaces of silicon and aluminium was investigated at room temperature by high resolution electron energy loss spectroscopy (HREELS) and reflection-absorption infrared spectroscopy (RAIRS). The molecular interaction was held under vacuum environment. The chemical state of the substrate surfaces was characterized before and after the alkoxysilane interaction by Auger electron spectroscopy (AES), HREELS or RAIRS. Under vacuum conditions, silica surfaces are chemically inactive to the TVES molecules contrarily to oxidized aluminium surfaces where adsorption is realized successfully. Differences among adsorption mechanisms on both substrates are discussed in light of Bronsted acid properties of the oxide surfaces and of the role of physisorbed water.