Ni-based　composite　coatings　reinforced　with　WC　particulates　were　fabricated　on　Q235　steel　by　vacuum　melting.　The　powders　of　Ni60A　alloy　and　WC　were　used　as　raw　materials.　The　transformation　of　WC　particulates　under　the　vacuum　brazed　processing　condition　was　studied　Results　show　that　prolonging　the　melting　time　has　great　effect　on　the　microstructure　of　composite　coatings　at　high　temperature　and　WC　transformation　occurs.　The　dominant　characteristics　are　that　it　transforms　into　needle　phase　on　the　verge　of　hard　phase;　with　the　melting　time　prolonging,　the　area　of　needle　phase　enlarges　and　turns　into　needle　congeries,　and　finally　transforms　into　a　mass　of　particle　phase.　XRD　analysis　indicates　the　particle　phase　is　Fe6W6C　with　complicated　cubic　structure,　which　reduces　the　hardness　of　the　coating　evidently.