Polycrystalline　indium　tin　oxide　(ITO)　is　one　of　the　important　materials　as　transparent　conducting　oxide　layer　in　thin　film　solar　cells,　digital　displays　and　other　similar　applications.　In　this　study,　ITO　films　were　deposited　onto　float　glass　substrates　by　RF　magnetron　sputtering　method　at　different　substrate　temperatures　(50-175　degrees　C)　with　discharge　power　of　60　Wand　work　pressure　of　0.25　Pa.　The　ITO　films　were　characterised　by　X-ray　diffraction,　scanning　electron　microscope　analysis,　optical　and　electrical　measurement.　The　structural,　optical　and　electrical　properties　of　the　ITO　films　show　a　strong　dependence　on　the　substrate　temperatures.　The　structural　and　electrical　measurement　results　indicate　that　the　donor　impurities　are　due　to　the　substitution　of　Sn　into　In　sites,　which　causes　an　expansion　of　the　lattice.　As　the　temperature　is　increased　from　50　to　175　degrees　C,　the　preferred　crystal　orientation　changes　from　[222]　to　[　100],　the　transmittance　in　the　visible　wave　band　is　beyond　80%,　and　the　electrical　resistivity　decreases　to　7.32　x　10(-4)　Omega.cm　at　175　degrees　C　substrate　temperature.　However,　the　optical　bandgap　is　slightly　increasing　with　the　increasing　of　the　substrate　temperature.