Abstract: Methyl esters were produced by trans-esterification of cottonseed oil with methanol in the presence of a homogeneous catalyst (KOH).A kinetic model was established by taking three consecutive and reversible reactions into consideration.Rate constants were determined for each reaction by the Runge-Kutta method with optimization.The corresponding values of frequency factor and activation energy were then obtained based on the Arrhenius’ law for all forward and reverse reactions under different experimental conditions.