p-c-BN/p-Si　thin　film　heterojunctions　have　been　fabricated.　BN　films　were　deposited　on　p-type　Si　wafers　using　RF　reactive　sputter,　and　were　doped　into　n-type　semiconductor　by　implanting　ions　into　them.　The　energy　of　implantation　of　ions　is　100　keV,　and　the　dose　of　implantation　is　1015　ions/cm2.　The　p-c-BN/p-Si　thin　film　heterojunctions　have　been　annealed　at　the　temperature　of　800°C.　The　I-V　(current-voltage)　characteristics　have　obvious　rectification.　The　fitting　results　show　that　current　transporting　model　for　the　p-c-BN/p-Si　thin　film　heterojunctions　is　the　same　as　current-voltage　equation　of　diode　and　the　donor　concentration　is　2.04　×　1013/cm3　in　the　c-BN　films.