WC-NiCrBSi　composite　coatings　on　0.45　%　carbon　steel　were　fabricated　by　laser　cladding.　The　volume　fraction　(33,　43　and　60　vol.　%)　of　WC　particles　with　the　powder　size　of　2　mu　m,　5　mu　m　and　50　mu　m　were　added　respectively　into　NiCrBSi　powders　to　deposit　composite　coatings.　The　microstructure　of　the　powders　and　the　coatings　were　examined　by　scanning　electron　microscope　(SEM)　and　X-ray　diffraction　(XRD).　Results　show　that　the　compactness　and　uniformity　of　the　coatings　are　good　when　WC　particles　size　was　2　mu　m　and　5　mu　m.　However　nonuniform　distribution　and　deposit　of　WC　particles　on　the　bottom　of　the　coating　will　occur　when　the　powder　size　of　WC　particles　was　50　mu　m　and　the　volume　fraction　of　WC　was　33　%.　When　the　volume　of　WC　addition　was　higher　than　60　%,　the　volume　fraction　of　the　retained　WC　particles　in　the　coatings　is　obviously　decreased.　The　dissolving　and　decomposing　of　WC　increase　with　decreasing　the　powder　size　and　increasing　the　volume　of　WC　addition　and　the　laser　power.