The feasibility of mesoporous silica as support to NiMo catalysts for hydrotreating of gas oil derived from Athabasca bitumen was tested in a trickle bed reactor at industrial conditions. High quality two dimensional (2D) hexagonal SBA-15 and three dimensional (3D) cubic KIT-6 supports were prepared by sol-gel method. The supports and catalysts were characterized by different characterization techniques such as N-2 physisorption, X-ray diffraction (XRD), Temperature programmed reduction (TPR), and DRIFT spectroscopy. The XRD and N-2 adsorption-desorption analysis shows the stability of structure after metal loadings. Presence of high NiMoS centres which is responsible for higher hydrotreating activities in KIT-6 supported catalysts is demonstrated by DRIFT spectroscopic analysis. HDN and HDS activities of NiMo catalysts supported on SBA-15 and KIT-6 were studied using coker light gas oil at temperature, pressure and LHSV of 370 degrees C, 8.8 MPa and 2.0 h(-1), respectively. KIT-6 supported catalysts shows much higher hydrodesulfurization (HDS) and Hydrodenitrogenation(HDN) activities compared to SBA-15 counterpart due to the fact that 3D-interconnected mesopores caused better dispersion of active species and faster diffusion of reactants and products.