Abstract: The CaO/La2O3 solid base catalysts were prepared by coprecipatation and used in the transesterification of soybean oil with methanol.XRD results showed that Ca and La produced good synergistic effects and the active component was highly dispersed.The suitable conditions for the catalyst preparation were as follows：n（Ca）/n（La）=2∶1，the calcination temperature was 750 ℃ and the calcination time was 3 h.The yield of biodiesel in the transesterification over the above catalyst was more than 90% under the conditions of the amount of substance ratio of methanol to oil of 13∶1，the mass ratio of catalyst to oil of 4% and the reaction time of 4 h.

Key words: CaO/La2O3；soybean oil；transesterification；solid base catalyst