In　the　present　study,　a　complete　route　which　integrates　in-situ　synthesis　of　WC-Co　composite　powder　and　sinter-HIP　is　proposed　to　prepare　the　ultrafine　tungsten　carbides.　Owing　to　the　in-situ　reduction　and　carbonization　reactions　of　WO2.9,　CO3O4　and　carbon　black　powders　at　1000　degrees　C,　the　composite　powder　with　pure　phase　constitution　and　ultrafine　particle　size　is　synthesized　with　a　rapid　procedure.　The　WC-Co　bulk　material　prepared　by　the　sinter-HIP　densification　of　the　composite　powder　exhibits　homogeneous　and　ultrafine　microstructure,　as　well　as　the　excellent　mechanical　properties.　The　proposed　method　shows　potential　to　be　developed　as　a　promising　industrial　route　owing　to　its　advantages　of　low-cost　raw　materials　and　short-term　in-situ　reactions.　(C)　2010　Elsevier　Ltd.　All　rights　reserved.