The　thin　film　temperature　sensor　chip　is　fabricated　with　the　Ti/Pt　film　layer　on　a　silicon　substrate　by　micro　electromechanical　systems　technology.　Using　electron　beam　evaporation,　10　and　100　nm　thick　Ti/Pt　films　layers　are　fabricated.　Then,　the　annealing　experiments　for　the　temperature　sensor　chip　are　carried　out　in　air　and　vacuum　at　400　degrees　C-800　degrees　C.　The　relationship　between　the　resistance　of　temperature　sensor　chip　and　tested　temperature　in　the　range　of　-30　degrees　C-150　degrees　C　is　studied　based　on　different　annealing　conditions,　and　its　electrical　characteristic　parameters　are　evaluated　including　temperature　coefficient　of　resistance　(TCR),　hysteresis　and　measuring　precision.　At　the　same　time,　the　morphology　and　grain　size　of　the　Pt　film　layer　are　studied　by　x-ray　diffractometer,　atomic　force　microscope　and　scanning　electron　microscope.　The　changes　of　square　resistance　and　internal　stress　are　tested　by　four　probes　and　stress　analyser　to　analyze　the　performance　of　the　temperature　sensor　chip.　The　testing　experiments　show　that　the　electrical　properties　of　the　temperature　sensor　chip　annealed　in　air　are　better　than　those　in　vacuum.　Finally,　the　temperature　sensor　chip　is　fabricated　with　the　optimal　performance　with　the　annealing　temperature　of　800　degrees　C　for　30　min　in　air.　Compared　with　before　annealing,　TCR　increased　by　75.4%　from　1790　to　3140　ppm　K-1,　hysteresis　reached　0.2%　FS　and　precision　reached　0.32%　FS.