A series of isomorphic lanthanide coordination polymers [Ln(III)(MBP)_2(NO_3)_2(Br)?2C_3H_6O] [Ln=Eu, Tb, Er, Yb, and Gd; MBP=N,N′-methylene-bis(pyridin-4-one)] featuring polycatenated sql cationic network and incorporated bromide counter ion were prepared. Their visible and near-infrared(NIR) luminescence properties were characterized by steady-state excitation and emission spectra, as well as luminescence lifetimes and quantum yields. The D_(2d) dodecahedron coordination geometry causes visible light excitations and strongly monochromatic emissions. The external heavy-atom environment induces remarkable enhancement on the NIR emissions. The sensitization processes are revealed by analyzing the electronic properties of MBP ligand. A series of isomorphic lanthanide coordination polymers [Ln (III) (MBP) _2 (NO_3) _2 (Br)? 2C_3H_6O] [Ln = Eu, Tb, Er, Yb, and Gd; MBP = (pyridin-4-one)] featuring polycatenated sql cationic network and incorporated bromide counter ion were prepared. Their visible and near-infrared (NIR) luminescence properties were characterized by steady-state excitation and emission spectra, as well as luminescence lifetimes and quantum yields. The D_ (2d) dodecahedron coordination geometry causes visible light excitations and strongly monochromatic emissions. The external heavy-atom environment induces remarkable enhancement on the NIR emissions. The sensitization processes are revealed by analyzing the electronic properties of MBP ligand.