Cu2SnS3　is　a　narrow-band-gap　semiconductor　material.　It　has　suitable　optical　and　electrical　properties　which　make　it　a　potential　absorber　layer　of　solar　cells.　In　this　paper,　Cu2SnS3　thin　films　were　successfully　obtained　by　sulfurizing　CuSnS2　thin　films　deposited　by　RF　magnetron　sputtering　at　temperatures　of　350-425°C　for　2　h　in　an　atmosphere　of　hydrogen　sulfide　and　nitrogen.　The　influence　of　the　sulfurization　temperature　on　the　electrical　and　optical　properties　of　the　Cu2SnS3　thin　films　was　investigated.　The　experimental　results　show　that　the　Cu2SnS3　thin　films　sulfurized　at　a　temperature　of　425°C　exhibit　better　properties　than　others.　The　mobility　and　resistivity　of　the　Cu2SnS3　films　are　9　cm　2/V·s　and　3　Ω·cm,　respectively.　And　its　optical　band　gap　is　estimated　to　be　about　1.77　eV.　©　2013　Pengyi　Zhao　and　Shuying　Cheng.