The　effects　of　W　content　and　preheat　temperature　on　combustion　temperature,　combustion　velocity　and　product　components　of　self-propagating　high-temperature　synthesis(SHS)　in　Ti-W-C　system　were　investigated.　The　results　show　that　with　decreasing　W　content　and　increasing　preheat　temperature,　the　combustion　temperature　and　combustion　velocity　increases,　the　SHS　reaction　becomes　complete　and　the　particle　size　of　product　increases.　There　exist　two　combustion　mechanisms.　When　Ti　powder　in　combustion　front　was　molten　by　high　combustion　temperature,　SHS　product　was　formed　by　melt-solution-precipitation　mechanism.　When　the　combustion　temperature　was　not　high　enough　to　make　Ti　powder　melt　in　combustion　front,　the　product　was　formed　through　diffusion-solution-in-solid-state.