Binary Al2O3-(15%)TiO2 and SiO2-(25%)TiO2 supports of hydrorefining Mo-Ni and hydrogenation Ni catalysts, resp., showed rutile to suppress catalyst activity. However, the Mo-Ni catalysts used for denitrogenation were more active with rutile as support constituent, and lower Mo-Ni contents could be used. Al2O3-(15%)TiO2 were prepared by co-precipitation; SiO2-(25%)TiO2 were prepared by hydrolyzing tetraisopropoxytitanium in i-PrOH or TiCl4 on the SiO2 surface. Properties of Al2O3-TiO2 were summarized in relation to impregnation, chemical vapor deposition, co-precipitation and mechanical mixing as support preparation mode. The effect of Ti on the texture, acidity, reducibility, and activity of hydrorelining Mo-Ni and hydrogenation Ni catalysts was presented.