The　adhesive　strength　to　the　substrate　plays　an　important　role　in　the　performance　of　thermal-sprayed　coatings　and　could　determine　the　coating＇s　service　life.　It　depends　to　a　large　extent　on　the　state　of　the　substrate　surface　prior　to　coating　deposition.　In　this　work,　a　novel　surface　pretreatment　technique　was　introduced　to　thermal　spraying,　namely,　bristle　blasting.　The　adhesive　strengths　of　a　plasma-sprayed　metallic　coating　(Ni5Al)　and　a　ceramic　coating　(Al2O3)　were　examined　and　compared　to　that　of　coatings　sprayed　with　conventional　grit　blasting　surface　pretreatment.　A　mild　steel　and　an　aluminum　alloy　were　selected　as　substrate　materials.　The　results　indicated　that　bristle　blasting　could　be　a　practical　solution　for　steel　and　aluminum　alloys　when　grit　blasting　is　not　applicable　on　site.　The　adhesion　of　the　sprayed　coatings　with　different　pretreatments　increased　sequentially　from　mechanical　grinding,　bristle　blasting　to　grit　blasting.　The　adhesive　strength　of　the　Ni5Al　coating　deposited　on　the　bristle-blasted　substrate　reached　60%　of　the　adhesive　strength　of　a　coating　deposited　with　the　traditional　grit-blasting　pretreatment,　while　for　the　alumina　coating,　it　was　only　about　30%.　Moreover,　the　effect　of　substrate　materials　should　be　considered　when　using　bristle　blasting　as　a　surface　preparation.