This study is focused on the transesterification of the soybean oil into biodiesel using magnetic based solid catalysts (LiFe5O8-LiFeO2). The catalyst was prepared through a simple solid-state reaction that involved mixing and grinding iron oxide (Fe2O3) and Li2CO3. The results demonstrated that the catalyst was ferromagnetic. Under the optimal reaction conditions, the highest FAME conversion in the transesterification of soybean oil can reach 96.5% by using LiFe5O8-LiFeO2 catalyst. The LiFe5O8-LiFeO2 demonstrates excellent catalytic activities and it could be recovered by magnetic separation. The LiFe5O8-LiFeO2 can be easily recovered and reused without significant deactivation.