ThethermalshockbehaviorofZrB2-20%SiC-6.05%ZrCcompositesfabricatedwithin-situmethod andhot-pressingwasstudiedbymeansofquenchingintowaterfromhightemperatures.Theeffectsofthermalshock temperaturedifferences,cool(25℃ofbathtemperature)andboilingwaterascoolingmedium,singleandfivecyclic shocksandhightemperatureoxidationonthermalshockresistanceofsamplesfabricatedthroughin-situmethodwere investigated.Thethermalshockresistanceparametersofsamplesfabricatedthroughin-situmethodandhotpressing werecomparedandthenthemechanismofthermalshockresistancewasalsodiscussed.Theresultsshowthatthermalshockpropertyofin-situsamplewasbetterthanthatofhot-pressingsample