Graphite oxide (GO) supported CaO catalysts were prepared and successfully applied to the transesterification of soybean oil with methanol. The supports and resultant catalysts were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), N(2) adsorption, thermogravimetry (TG), X-ray photoelectron spectroscopy (XPS), temperature-programed desorption (TPD) and Fourier-transform infrared spectroscopy (FT-IR). The GO supported CaO catalysts exhibited excellent catalytic activity and were easily regenerated by simple heat-treatment. The oxygen-containing groups (i.e., hydroxyl, epoxide groups and carboxyl groups) present on the surface of GO likely act as anchoring centers for CaO. This work demonstrates that graphite oxide is an effective host material of catalytically active CaO nanoparticles for the transesterification of soybean oil with methanol to produce biodiesel. (C) 2011 Elsevier Ltd. All rights reserved.