Abstract: A solid base catalyst supported on bentonite was introduced and used in the transesterification process for biodiesel production. The catalyst was prepared by adsorbing sodium hydroxide into the layers of semi-dried alkaline Ca-bentonite. The results of single factor experiments for catalyst preparation showed that the optimum conditions are：the mass ratio of NaOH and alkaline Ca-bentonite is 0.6，the loading time is 18 h，the temperature is 60 ^oC，and the OH^− contained in alkaline Ca-bentonite is 1.5 mmol∙g^−1，respectively，with which the loading amount of NaOH is 4.10 mmol∙g^−1. The transesterification conversion to biodiesel can be reached to 97.4% with the prepared catalyst，and the obtained biodiesel is no need to wash，which can avoid the release of a large amount of waste water and protect environment from being polluted.