The comparative effect of reaction severity at variation of the temperature (410–440°C) and time (0.5–4h) in the presence and absence of Mo-octoate on VR hydrocracking was studied. In the presence of 250ppm Mo improved selectivity of naphtha and middle distillate fractions. The SARA and H2 consumption results showed the different tendency of asphaltene conversion during thermal and catalytic hydrocracking. Asphaltenes seemed to be the main fraction converted to coke during hydrocracking reaction. For understanding the tendency of coke formation during hydrocracking of various asphaltene content feedstocks, the effect of asphaltene content on MCR, H/C ratio, Mn, and Ni, V, N, S content of feedstocks was investigated.