Investigations were conducted on heterogeneous base catalysts for the transesterification of oil aimed at effective production of biodiesel. Thirteen different kinds of metal oxides containing calcium, barium, magnesium, or lanthanum were prepared as catalysts. Their catalytic activities were tested for transesterification at 60 degrees C with a 6:1 molar ratio of methanol to oil and a reaction time of 10h. The calcium-containing catalysts - CaTiO3, CaMnO3, Ca2Fe2O5, CaZrO3, and CaO-CeO2 - showed high activities and approximately 90% yields of methyl ester. Furthermore, catalytic durability tests were performed by repeating the transesterification reaction several times with the calcium-containing catalysts recovered from the previous reaction mixture. It was found that CaZrO3 and CaO-CeO2 show high durability and have the potential to be used in biodiesel production processes as heterogeneous base catalysts.