A new 2D metal-organic coordination polymer [Ce(3,4-pydc)2]·H2O(1) was synthesized by hydrothermal reaction of Ce(NO3)3·6H2O and 3,4-pydc (3,4-pydc = 3,4-pyridinedicarboxylate). The structure was characterized by elemental analysis and IR spectroscopy. Single crystal was determined by X-ray single crystal diffractometer. The crystal belongs to monoclinic crystal system and P2(1)/c space group. Crystallographic data: a = 14.501(3) nm, b = 6.7980(19) nm, c = 14.590(3) nm, α = 90°, β = 94.497(2)°, γ = 90°, V = 1433.8(5) nm3, Z = 4. X-ray analysis reveals that the complex is a two-dimensional thick belt structure, and the hydrogen-bonding and p-p stacking interactions between belt layers extend the complex into a 3D supramolecular architecture.