In　this　paper,　we　introduced　light　and　abundant　metal　magnesium　into　a　cobalt-based　metal　organic　framework　(Co-MOF,　[(CH3)(2)NH2](2)[Co-3(bpdc)(4)]center　dot　5DMF　center　dot　4CH(3)OH)　(1,　H(2)bpdc　=　4,4＇-biphenyldicarboxylic　acid,　DMF　=　N,N-dimethylformamide)　as　a　heteroatom　to　synthesize　Mg-Co　bimetallic　MOFs,　namely　[(CH3)(2)NH2](2)[MgCo2(bpdc)(4)]center　dot　4DMF　center　dot　5CH(3)OH　(2)　and　[(CH3)(2)NH2](2)[Mg1.2Co1.8(bpdc)(4)]　4DMF　center　dot　4CH(3)OH　center　dot　6H(2)O　(3).　Based　on　the　formation　of　a　rather　low　density　framework　after　the　introduction　of　the　light　Mg2+,　such　bimetallic　MOFs　exhibited　higher　gas　adsorption　abilities　than　the　isostructural　Co-based　MOF　1.　N-2　adsorption　measurements　demonstrate　that　the　BET　surface　area　of　3　is　305.4　m(2)　g(-1),　exhibiting　three　times　that　of　1　(104.4　m(2)　g(-1)).　Significantly,　due　to　the　introduction　of　the　low-melting　Mg2+,　the　Mg-Co　MOFs　could　be　further　utilized　as　precursors　for　porous　carbons　only　by　calcination　at　a　mild　temperature　of　600　degrees　C　which　could　exhibit　a　BET　surface　as　high　as　712.78　m(2)　g(-1).　Furthermore,　after　post-synthetic　modification　with　a　N/S　heteroatom　at　900　degrees　C,　the　obtained　hierarchical　carbons　exhibit　superior　activity　in　the　oxygen　reduction　reaction　(ORR)　that　is　comparative　to　the　commercial　Pt/C　catalyst.　TEM　results　indicate　that　Co-embedded　carbon　nanotube　(CNT)-containing　hierarchically　nanoporous　carbons　have　been　obtained.　This　study　may　offer　a　new　avenue　to　prepare　porous　carbons　utilizing　Mg-containing　bimetallic　MOFs　as　sacrificial　templates.