The theory of normal pulse voltammetry (NPV) for complex multistep multielectron transfer processes on a plane electrode was advanced and applied to the completely irreversible process of methanol oxidation to formic acid in the potential range from 0.3 to 0.8 V versus Ag/AgCl. The kinetic parameters for this process, such as the standard rate constant (k(0)) and anodic transfer coefficient (alpha) for this irreversible heterogeneous electron transfer process at the electrode/solution interface and apparent diffusion coefficient (D-app) for the homogeneous charge transfer process within liquid film near the electrode surface, were obtained with NPV theory from analyzing the dependence of current-potential curves upon the sampling times. The results showed that this process is truly a very slow, completely irreversible kinetic process, as k(0) is in the order of 10(-9) cm/s for the rate-determining step. The values of k(0) and D-app decreased with the increase of methanol concentration, while alpha was independent of the concentration of methanol and its value was 0.35 +/-0.05. Theoretical fitting is very consistent with the experimental data.