The　supersonic　plasma　sprayed　WC-12Co　coatings　have　a　higher　micro-hardness　and　bonding　strength　as　particles　flying　velocity　(about　400-500　m/s)　is　much　faster　than　that　(about　200　m/s)　sprayed　by　common　plasma　approach.　The　examinations　of　SEM　microstructure　and　XRD　phases　showed　that　the　synthesis　porosities　of　WC-12Co　coatings　by　supersonic　plasma　sprayed　is　superior　to　that　of　common　plasma　sprayed.