Presented　herein　are　two　luminescent　magnesium　coordination　polymers　(Mg-CPs),　namely　[Mg2(H2O)2(2-NDC)4(1,10-phen)2]　(1)　and　[Mg2(H2O)(1,4-NDC)2(1,10-phen)]　(2),　in　which　2-NDCH=2-naphthalenecarboxylic　acid,　1,4-NDCH2=1,4-naphthalene　dicarboxylic　acid,　and　1,10-phen=1,10-phenanthroline.　Based　on　the　mixed　ligands,　the　title　compounds　exhibit　linker-based　photoluminescence　(PL)　properties　thanks　to　the　unique　configuration　of　the　Mg2+　ions.　The　two　compounds　show　interesting　dual　emission　on　excitation　of　the　different　luminophores　of　the　mixed　linkers.　In　particular,　the　emissions　of　compound　2　could　be　tuned　from　green　to　yellow　simply　by　varying　the　excitation　energies.　Furthermore,　2　could　be　excited　by　using　a　commercial　λ=450　nm　blue　LED　chip　to　generate　white-light　emission,　which　allows　the　fabrication　of　a　white-light-emitting　diode　(WLED)　with　20　lm　W-1　luminous　efficacy.　This　work　may　provide　a　new　method　for　designing　tunable　PL　CPs　by　using　the　low-cost　and　abundant　magnesium　ion.　Get　coordinated:　Two　dual-emission　luminescent　magnesium　coordination　polymers　were　prepared　based　on　mixed　ligands.　The　emission　of　one　compound　could　be　simply　tuned　by　varying　the　excitation　energy,　and　could　be　excited　by　using　a　commercial　λ=450　nm　blue　LED　chip　to　generate　white-light　emission　with　20　lm　W-1　luminous　efficacy　(see　figure).　©　2016　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim.