A 4d-4f heterometallic coordination polymer, [AgNd(pydc)2]?2H2O (1) (H2pydc=pyridine-3,4-dicarboxylic acid), was synthesized under hydrothermal conditions, and further characterized by elemental analysis, IR, thermogravimetric analysis and single-crystal X-ray dif-fraction. Complex 1 featured a three-dimensional (3D) framework containing one-dimensional (1D) channels occupied by free water molecules, which was constructed from 1D inorganic heterometallic chains and linear pydc linkers. To our knowledge, complex 1 represented a rare example of 3D open-framework 4d-4f heterometallic coordination polymer. After removal of the water molecules from complex 1, the remaining material had high thermal stability. Moreover, the near-infrared luminescent properties of 1 were also investigated in the solid state. A 4d-4f heterometallic coordination polymer, [AgNd (pydc) 2] 2H20 (1) (H2pydc = pyridine-3,4-dicarboxylic acid), was synthesized under hydrothermal conditions, and characterized by elemental analysis, IR, thermogravimetric analysis Complex 1 featured a three-dimensional (3D) framework containing one-dimensional (1D) channels occupied by free water molecules, which was constructed from 1D inorganic heterometallic chains and linear pydc linkers. To our knowledge, complex 1 represented a rare example of 3D open-framework 4d-4f heterometallic coordination polymer. After removal of the water molecules from complex 1, the remaining material had high thermal stability. Moreover, the near-infrared luminescent properties of 1 were also investigated in the solid state.