The purpose of this research was to investigate the catalytic activity of Ba loading on calcium oxide (CaO) catalyst by varying the amount of barium added during the synthesis: 5-15 wt%. The waste egg shells were utilized as a CaO heterogeneous catalyst by calcined at 900 °C for 2 h. The Ba/CaO catalysts were prepared by impregnation method and were used as a catalyst in transesterification reaction of canola oil via microwave irradiation under microwave power 300 W. The characterization of catalyst and FAME composition of biodiesel were determined by X-ray fluorescence (XRF), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), and gas chromatography (GC-FID). The conditions of biodiesel production were operated at 60 °C, 3 wt% of catalyst loading, 9:1 methanol-to-canola oil ratio, and microwave irradiation power was 300W for 2 min. The experimental results found that, the waste egg shells consist mainly of CaCO3, which was decomposed to CaO more than 88 wt% after cacination step. The 15 wt% Ba/CaO catalysts exhibited the best catalytic performance with the FAME conversion higher than 97.68%.