By using palm oil as feedstock, methanol as an esterifying agent, and CaO-La2O3 as the catalyst, effects of the reaction condition on concentration of methyl esters were researched. The best reaction time, amount of catalyst, and ratio of methanol and palm oil were and 3.5 h, 2.5%, and 15: 1, respectively. According to the guiding principles of reaction kinetic model mechanism, reaction kinetics model of biodiesel is pointed out. Model simulated data are close to experimental data.