The　mixed　powder　of　WO3　and　carbon　was　in-situ　synthesized　to　get　the　dense　WC　bulk　by　a　spark　plasma　sintering　technique.　The　effects　of　the　synthesis　parameters　and　the　carbon　contents　on　the　phase　composition,　the　density　and　microstructure　of　the　bulk　have　been　studied.　The　results　showed　that　the　carbon　can　rapidly　reduce　the　WO3　to　W　and　directly　carbonize　it　at　860　degrees　C　similar　to　1　060　degrees　C,　leading　to　a　sintering　reaction　with　the　temperature　increasing.　When　the　carbon　content　is　low,　the　W　or　W2C　still　existed　in　the　bulk　as　impurity.　But　when　the　carbon　content　is　appropriate,　WC　existed　only　and　the　density　of　bulk　can　be　near　the　theoretical　density　with　a　grain　size　of　about　500　nm.