Self-assembly of phosphonic acid (5-pncH3=(5-phosphono-1-naphthalenecarboxylic acid) and copper perchlorate hexahydrate, 1D coordination polymer, namely Cu0.5(5-pncH2)(H2O)1.5 (1) was hydrothermally synthesized. The crystal structure and thermal stability were characterized by single-crystal X-ray diffraction, EA, FT-IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TG-DTG). Structure analyses reveal that compound 1 crystallized in the orthorhombic system, space group Pbcm, a=0.667 88(2) nm, b=0.884 14(2) nm, c=4.174 03(9) nm. Compound 1 has a one-dimensional chain structure, in which the adjacent CuII ions are bridged into a one-dimensional zigzag chain through the coordination water molecules. The two-dimensional layered structure is formed by the double hydrogen bond of carboxyl group on the organic phosphonic acid ligand. The thermal stability study shows that the complex exhibits a step-by-step decomposition process, and the stability of the complex skeleton structure can be maintained below 350 ℃.