Abstract: Swamp meadow in Aershan city, Inner Mongolia Autonomous Region was taken as the research area, the typical herbaceous Leymuschinensis was taken as the research object, and the thermogravimetric analysis was used to study the thermogravimetric behavior under the conditions of oxygen flow rate of 10, 20, 30 mL/min and heating rate of 40，80 ℃/min, respectively. TG-DTG curve were used to analyze the pyrolysis process of the sample, and Coats-Redfern (CR) integration method and Flynn-Wall-Ozawa (FWO) integration method were used to analyze the kinetics of the rapid pyrolysis stage of the sample to obtain the pyrolysis activation energy, pre-exponential factor and corresponding parameters of the sample under different oxygen concentrations. The results showed that the pyrolysis process of Leymus chinensis can be divided into three stages: dehydration stage, rapid pyrolysis stage and carbonization stage, in which the rapid pyrolysis stage is 350~450 ℃. In this stage, the faster the heating rate is, the more obvious the temperature lag is; the faster the oxygen flow rate is, the more obvious the temperature advance is. The analysis of pyrolysis process and kinetic parameters showed that FWO method is more suitable for the pyrolysis process of Leymus chinensis, and the oxygen flow rate that causes fires is 30 mL/min＞20 mL/min＞10 mL/min.

Key words: thermogravimetric analysis, pyrolysis characteristics, swamp meadow, Leymus chinensis, forest fires, China-Mongolia border