An algorithm and a computer program for the evaluation of kinetic parameters under constant reaction rate conditions were elaborated. The computing procedure allows the observation of reaction mechanism changes as well as the evaluation of activation parameters. The algorithm was tested using some simulated decomposition curves as well as the constant rate decomposition curves of calcium oxalate. The program is written in Visual BASIC 3.0 and 4.0 and can run under MS Windows 3.1x or Windows 95(C).