PURPOSE: To carry out hydrotreatment of heavy oil producing little coke in the product oil and giving a prolonged catalyst life, by hydrotreating the heavy oil using a catalyst comprising V and Ni supported on allophane and an inorg. heat- resistant binder.

CONSTITUTION: Heavy oil is hydrotreated under conditions including a reaction temp. of 400W600°C and a pressure of 1atmW200kg/cm2 using a catalyst comprising V and Ni supported on a carrier consisting of 50W80wt% allophane and 20W 50wt% inorg. heat-resistant binder, in which 1W20pts.wt. V and 0.5W10pts.wt. Ni are supported on 100pts.wt. carrier. Said allophane is colloidal soil usually called Kuri-soil, Miso-soil, Mizu-soil, or Uki-ishi-soil, which has unigue adsorptivity. The inorg. binder includes alumina gel, silica gel, or the like. The component binds allophane particles to enhance mechanical strength of the whole body and itself is porous and has a catalytic activity.