Heterogeneous transesterification of vegetable oils offers an environmentally more attractive option for biodiesel production compared to the conventional homogeneous processes. In the work, a novel heterogeneous base catalyst was prepared by anchoring 1,3-dicyclohexyl-2-octylguanidine (DCOD) onto the mesoporous SBA-15 silica. The DCOG-functionalized SBA-15 material (SBA-15-pr-DCOG) was demonstrated to be an efficient and recyclable heterogeneous catalyst for the transesterification of soybean oil with methanol. The characterization of the catalyst was carried out using Hammett titration method, Xray diffraction, Fourier transform infrared spectroscopy, thermo gravimetric and differential thermal analysis, transmission electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption desorption techniques. It was shown that the DCOD was successfully tethered on the SBA-15 silica and ordered mesoporous structure of SBA-15 was largely remained unchanged after the functionalization reaction. The influences of transesterification variables such as the methanol/oil molar ratio, catalyst loading, reaction time, and catalyst reusability on the oil conversion were investigated. By using the methanol/oil molar ratio of 15:1 and catalyst loading of 8 wt%, the maximum oil conversion of 92.6% was achieved over the solid catalyst at reflux of methanol for 15 h. The heterogeneous base catalyst could be easily recovered and reused for several runs with a negligible loss of activity. (C) 2015 Elsevier Ltd. All rights reserved.