A　numerical　study　on　methane/air　combustion　inside　a　microchannel　was　undertaken　to　investigate　the　effects　of　inlet　velocity,　equivalence　ratio,　and　convective　heat　transfer　coefficient　on　combustion　characteristics.　The　simulation　results　show　that　the　inlet　velocity　has　a　strong　influence　on　the　reaction　zone,　and　the　flame　front　shifts　downstream　as　the　inlet　velocity　increases.　The　influence　of　inlet　velocity　on　convection　heat　transfer　between　mixture　and　walls　is　significant　and　the　temperature　difference　between　mixture　and　walls　in　the　inlet　section　increases　with　the　inlet　velocity　first　to　a　certain　value　and　then　decreases.　The　equivalence　ratio　is　a　key　parameter　that　affects　the　combustion　characteristics.　The　highest　flame　temperature　is　obtained　if　the　equivalence　ratio　is　set　at　1.0.　The　reaction　rate　of　the　equivalence　ratio　equal　to　0.8　is　larger　than　that　of　the　equivalence　ratio　equal　to　1.0　and　1.2.　The　steady　flame　cannot　be　obtained　with　a　0.6　equivalence　ratio　and　0.5　m/s　inlet　velocity.　However,　when　the　inlet　velocity　is　increased　to　0.7　m/s,　a　steady　flame　is　observed.　The　convective　heat　transfer　coefficient　shows　a　very　strong　influence　on　combustion　characteristics.　With　the　increase　of　heat　transfer　coefficient　on　external　walls,　the　wall　temperature　and　downstream　fluid　temperature　decrease.　However,　the　influence　is　weakened　at　the　inlet　section.　No　oscillatory　behavior　is　observed　when　the　heat　transfer　coefficient　is　less　than　50　W/(m(2)　.　K)　and　the　steady　flame　cannot　be　obtained　if　the　heat　transfer　coefficient　is　set　at　100　W/(m(2)　.　K).