The role of dispersed catalyst in hydroconversion of heavy vacuum residue is to suppress the cause formation and promate the upgrading reaction sulfur, nitrogen, metals removal and conradson carbon reduction.  In this study, the effect of temperature (350- 425ºC) and catalyst/feed ratio (1/10, 2/10 and 3/10) on the hydrodemetallation (HDM), hydrodesulphurization (HDS), conradson carbon removal and product distribution of heavy vacuum residue has been investigated. Three spent catalyst are used which produced from different refining processes. Comparison between the yield and performance of the product by using the three spent catalysts at 400ºC and catalyst/free ratio 2/10 shows that HDS, HDM and conradson carbon removal for spent catalyst produced from hydrodesulphurization of kerosene was higher than that of spent catalyst produced from hydrodesulphurization of gas oil and spent catalyst produced from rerefining of waste lube oil.