The low stability of the fuel oil from vacuum residue hydro-cracking process (HRGO) limits its application as a direct component of commercial products. Consideration was given to the influence of group components, and the effect of hydrodesulphurisation and hydrogenation processes on the HRGO stability. It was found that hydrodesulphurisation of HRGO carried out under mild conditions (Ni-Mo/Al2O3, 340degreesC, pressure 3 MPa, H-2:CH ratio 350:1 Nm(3)/ m(3) and LHSV 3 h(-1)) did not eliminate the compounds responsible for the product darkening. The results have shown that it is useful to apply a catalyst of increased hydrogenation activity.