A　series　of　SnO2　thin　films　doped　with　low-dose　Al　(＜=　1mol%)　were　prepared　on　slide　glass　substrates　by　radio　frequency　(RF)　magnetron　sputtering.　The　crystal　structure　and　optical　properties　were　investigated　by　X-ray　diffraction　(XRD),　scanning　electron　microscopy　(SEM),　UV-IR　spectrometer,　and　photoluminescence　(PL)　measurements.　Results　show　that　the　lattice　constant　c　decreases　with　increasing　the　Al　content,　which　implies　that　Al　atoms　are　successfully　introduced　into　the　SnO2　and　occupy　the　Sn　sites,　and　large　number　of　oxygen　vacancies　are　generated.　The　average　transmittance　values　are　higher　than　88%　within　the　visible　spectral　region　(400-800　nm)　for　all　the　films.　The　bandgap　broadens　when　the　Al　percentage　increases,　which　is　dominated　by　the　Burstein-Moss　(BM)　effect.　The　PL　spectra　of　these　films　have　near　band　edge　and　deep　level　emission　under　the　radiation　excitation　of　265　nm　wavelength.　The　observed　intensify　of　these　peaks　increases　consistently　with　increasing　the　Al　percentage.