Abstract: In order to create a molecular recognition property, tin oxide surface was modified by a chemical vapor deposition (CVD) method of silicon alkoxide using pre-adsorbed benzaldehyde as a template. The adsorption of aldehydes with different molecular sizes on silica-deposited tin oxide was studied at various temperatures. The molecular sieving property thus created was controlled by a steric hindrance between the silica overlayer and the adsorbates. The silica overlayer prepared by the CVD using alpha-naphthaldehyde showed a different adsorption property from the sample prepared using benzaldehyde. Thus, the molecular sieving property of silica overlayer could be adjusted by the selection of the template molecule. (C) 1997 Elsevier Science B.V