Lithium/sodium　metal　batteries　have　attracted　enormous　attention　as　promising　candidates　for　high-energy　storage　devices.　However,　their　practical　applications　are　impeded　by　the　growth　of　dendrites　upon　Li/Na　plating.　Here,　we　report　that　holey　2D　N-doped　TiNb2O7　(N-TNO)　nanosheets　with　high　electroactive　surface　area　and　large　amounts　of　lithiophilic/sodiophilic　sites　can　effectively　regulate　Li/Na　deposition　as　an　interfacial　layer,　leading　to　an　excellent　cycling　stability.　The　N-TNO　interfacial　layer　enables　the　Li　parallel　to　Li　symmetric　cell　to　sustain　stable　electrodeposition　over　1000　h　as　well　as　the　Na　parallel　to　Na　cell　to　stably　cycle　for　2400　h　at　1　mA　cm(-2)　and　3　mA　h　cm(-2)　with　a　depth　of　discharge　as　high　as　50%.　The　full　cells　of　the　Li/Na　anodes　based　on　the　N-TNO　layer　paired　with　the　LiFePO4　and　NaTi2(PO4)(3)　cathodes,　respectively,　show　a　very　stable　cycling　over　1000　cycles　at　a　negative-to-positive　electrode　capacity　(N/P)　ratio　up　to　3.