Abstract: Residua hydrotreating (RHT) has received considerable attention with the increasing tension and inferior quality of oil resources. Therefore，the disadvantage influence of nickel and vanadium in heavy oils to RHT process，complete removal of them is one of the significant and difficult problem in technologies of RHT. In this paper，the progress in mechanism of residue hydrodemetallization is summarized from three points of the interaction between metal-porphyrin and surface of catalyst，intermediates and reaction models and the modification effect of several influence factors on reaction process. Besides that，the present imperfections and directions in the future are also propounded.