A new approximation for the temperature integral has been obtained by using Pattern Search method. The corresponding equation for the evaluation of kinetic parameters is presented, which can be put in the form ln[8(alpha)/T-2] = ln[AR/beta E E+ 0.66691RT/2.64943RT] - E/RT The validity of the new temperature integral approximation has been tested by numerical calculation. Its deviation from the values calculated by numerical integrating was discussed. Compared with several published approximate formulas, this new one is much superior to all other approximations, and is the most suitable solution for the evaluation of kinetic parameters from nonisothermal kinetic analysis. (c) 2006 American Institute of Chemical Engineers.