The adsorption of Ni-8 clusters on the anionic (Mg25O240/+/2+, F-s(0/+/2+)) and cationic (Mg24O250/-/2-, V-s(0/-/2-)) vacancies, as well as on the regular sites (Mg25O25, Mg2+ and NiMg24O25, Ni2+) of the MgO(001) surface has been investigated at the PW91/DND level of density functional theory. On the basis of the computed adsorption energies, the metal deposition has the decreasing order of Ni-8/V, > Ni-8/V-s(2-), Ni-8/F-s(2-) > Ni-8/F(s)2(+) approximate to Ni-8/Ni2+ approximate to Ni-8/F-s(+) approximate to Ni-8/Mg2+ > Ni-8/F-s > Ni-8/O2-. Strong electron and charge transfers are found between Ni-8 cluster and vacancies or regular sites. The electronic property of the vacancies has been analyzed.