Abstract: In this paper,pellets made of eucalyptus sawdust which is a typical biomass in southern China were taken as the research object.Raw materials and the delaminated layer of pellets were carried out to study the combustion characteristics changes by thermogravimetric analysis technology,and the combustion reaction kinetics parameters were calculated by Coasts integral method.The results showed that while the ignition temperature of the pellets decrease,the flammability and combustion characteristics of the outer fuel become better,the activation energy and pre-exponential factor increase in the devolatilization and combustion stage,but decrease in the fixed carbon combustion stage,which indicates that the thermal stability of eucalyptus sawdust becomes better and more difficult to burn after molding,while the thermal stability becomes worse and easier to burn in fixed carbon combustion stage.