This paper has presented some popular methods used to determine the kinetic parameters from nonisothermal thermogravimetric analysis (TGA) data. These methods include the improved Doyle-Ozawa method, and the nonlinear regression method. The above-mentioned methods along with a new method proposed by the present authors are compared with the true thermogravimetric data generated by the synthetic TG/DTG curves. This paper has shown that the proposed E-2-function method has the advantages of both reliability in calculation and straightforwardness in formulation.