The pyrolysis kinetics of invasive plant Spartina anglica biomass was investigated via a thermogravimetric (TG) analyzer from 50 to 800 degrees C in an inert argon atmosphere at different heating rates of 5-30 degrees C/min, and the kinetic parameters were deduced by Starink and master-plots methods. The results showed that three stages appeared in the thermal degradation process, and the mean value of activation energy was calculated to be 291.57 kJ/mol by the Starink method. It suggested that the most probable pyrolysis kinetic model was g(a) = [-ln(1-a)](4) deduced by the master-plots method, which meant a random nucleation and nuclei growth mechanism. These results provided fundamental useful information for describing the pyrolysis process, and the subsequent designing and running of a pyrolytic processing system using S. anglica as feedstock.