The　La　0.96Sr　0.04MnO　3/　SrNb　0.01Ti　0.99O　3　p-n　heterojunction　fabricated　by　the　magnetron　sputtering　technique　exhibits　excellent　rectifying　characteristics　over　the　temperature　range　from　20　to　300　K.　From　fitting　results　of　the　I-V　curves,　it　is　found　that　the　electrical　transport　properties　of　the　hetero-structure　are　mainly　affected　by　the　thermal　activation　effect　above　100　K.　Moreover,　the　heterojunction　exhibits　obvious　metal-insulator　transition　at　170　K,　the　curve　of　temperature　vs.　resistance　shows　an　insulator　→　metal　→　insulator　transition　process.　Under　a　magnetic　field　of　5　T,　the　magnetoresistance　(MR)　of　the　heterojunction　increases　from　negative　to　positive　with　the　temperature　increasing　under　forward　voltages.　And　an　opposite　process　occurs　under　reverse　voltages.　The　largest　negative　MR　is　-50.6%　under　reverse　voltage　of　-1　V　at　the　metal-insulator　transition　temperature.