Hydrodesulfurization (HDS) of dibenzothiophene in a batch reactor was performed at 5.5MPa and 320 degrees C on CoMoS/Al2O3-TiO2 using trans-1,2-cyclo-hexanediamine-N,N,N',N'-tetraacetic acid (CYDTA) as a complexing agent for the preparation method. The effects of titania, concentration of CYDTA, and preparation procedure were investigated by using X-ray diffraction, BET, Fourier transform infrared spectroscopy, and temperature-programmed desorption of ammonia experiments. The catalyst prepared by impregnation with gamma-alumina and titanium isopropoxide as raw materials and a CYDTA/Co mole ratio of 1.2 provided an HDS activity (on a pseudo-first-order kinetic constant basis) value similar to 3.8 times higher compared to that of a CoMo/Al2O3 catalyst.