Fresnoite　(Ba2TiSi2O8,　BTS)　thin　films　were　grown　on　polished　Si(100)　substrates　by　sol-gel　method.　The　films　were　characterized　using　Fourier　transform　infrared　spectroscopy　(FTIR),　Raman　scattering　spectroscopy,　X-ray　diffraction　(XRD)　and　atom　force　microscopy　(AFM).　The　results　reveal　that　the　crystallinity　of　fresnoite　thin　films　increases　and　their　structures　become　more　compact　as　post-annealing　temperature　increases.　Combined　with　XRD　data,　the　strong　FTIR　peaks　and　Raman　bands　assigned　to　Ti-O　and　Si-O　vibration　indicate　the　formation　of　fresnoite　phase　in　the　films　at　a　temperature　of　750　degreesC.　Besides,　the　AFM　observation　showed　the　films　have　a　smooth　surface,　fine　grains　and　dense　structure.　(C)　2004　Elsevier　B.V.　All　rights　reserved.