By using palm oil as feedstock and methanol as an esterifying agent and CaO-La2O3 as the catalyst, effects of different catalyst's activity and synthetic methods for biodiesel's yield were researched. When the ratio of CaO and La2O3 and calcination's temperature was 2.0:1.0 and 1,073 K, respectively, CaO-La2O3 had a good activity and stabilization. The co-settling method has the highest catalyst's activity and biodiesel yield than that of other methods. The optimizing reaction temperature, reaction time, amount of catalyst, and ratio of methanol of palm oil were 70 degrees C, 3.5 h, 2.5%, and 15:1, respectively. When CaO-La2O3 was reused five times, CaO-La2O3's activity kept above 90%.