The　Al-doped　Mg2Si　thin　films　were　fabricated　by　two-target　alternative　magnetron　sputtering　technique,　and　the　influences　of　different　Al　doping　contents　on　the　thermoelectric　properties　of　Al-doped　Mg2Si　thin　films　were　investigated.　The　compositions,　crystal　structures,　electronic　transport　properties　and　thermoelectric　properties　of　the　thin　films　were　examined　using　energy　dispersive　X-ray　spectroscopy　(EDS),　X-ray　diffraction　(XRD),　Hall　coefficient　measurement　and　Seebeck　coefficient　measurement　system,　respectively.　The　EDS　results　show　that　the　thin　films　doped　with　Al　target　sputtering　power　of　30　W,　60　W　and　90　W　have　the　Al　content　of　0.68　at.%,　1.56　at.%　and　2.85　at.%,　respectively.　XRD　results　indicate　that　the　diffraction　peaks　of　Mg2Si　become　stronger　with　increasing　Al　dopant.　The　results　of　Hall　coefficient　measurement　and　Seebeck　coefficient　measurement　system　reveal　that　all　the　samples　are　n-type.　The　conductivities　of　Al-doped　Mg2Si　thin　films　are　significantly　greater　than　that　of　undoped　Mg2Si　thin　film,　and　increase　with　increasing　Al　doping　content.　With　the　increase　of　temperature,　the　absolute　value　of　the　Seebeck　coefficients　of　Mg2Si　base　thin　films　increase　firstly　and　then　decrease.　The　maximum　power　factor　obtained　is　3.8　mW　m-1　k-2　for　1.56　at.%　Al-doped　Mg2Si　thin　film　at　573　K.　©　2016　Elsevier　B.V.　All　rights　reserved.