The　combustion　characteristics　and　SO2　release　of　petroleum　coke　have　been　studied　under　different　experiment　conditions　by　thermogravimetric　analyzer.　The　atmospheres　were　10%O2/90%N2,　20%O2/80%N2,　30%O2/70%N2.　Four　heating　rates,　from　10Kmin-1　to　40Kmin-1,　and　three　particle　sizes　were　used.　The　experimental　results　show　that　the　ignition　temperature　and　the　burnout　temperature　rise　with　increasing　heating　rate　and　decreasing　oxygen　concentration.　The　combustion　index　SN　indicates　that　smaller　particle　size　or　higher　heating　rate　and　oxygen　concentration　can　improve　the　combustion　reactivity　of　the　petroleum　coke.　SO2　release　and　desulfurization　with　additive　limestone　(Ca/S=　0∼2.4)　show　that　the　desulfurization　efficiency　increases　from　47.8%　to　97.9%　with　increasing　Ca/S.