WC-Co　composite　powder　was　synthesized　with　carbon　black　and　W,　Co　oxides　as　raw　materials　and　VC　as　additive　by　the　in-situ　reduction　and　carbonization　process.　The　nanocrystalline　WC-Co　alloys　were　fabricated　by　the　spark　plasma　sintering　technique　using　the　prepared　WC-Co　composite　powder.　The　phase　composition,　microstructure　characteristics　and　mechanical　properties　of　the　sintered　cemented　carbides　were　analyzed.　The　results　show　that　VC　addition　plays　a　significant　role　in　phase　composition,　grain　size　and　properties　of　the　prepared　WC-Co　alloy.　When　the　VC　addition　is　2.0%,　the　average　grain　size　is　101　nm,　the　phases　are　WC　and　Co,　and　the　cemented　carbides　possess　high　hardness　and　good　fracture　toughness.