A metal-organic coordination polymer [Cd2(C6H8N2O2)2Cl4]n·3nH2O [where C6H8N2O2 is ionic liquid, 1-carboxymethyl-3-methylimidazolium] 1 has been hydrothermally synthesized and characterized by X-ray diffraction single-crystal structure analysis. The complex crystallizes in orthorhombie, space group Aba2 with a= 1.747 6(3) nm, b=1.933 6(4) nm, c=0.692 75(13) nm, V=2.3409(8) nm3, Mr=700.96, Dc=1.989 g·cm-3,μ(Mo Ka)=2.312 mm-1, F(000)=1 368, Z=4, the final R=0.021 4 and wR=0.051 2 for 3 331 observed reflections (1>2σ(I)). Each Cd(Ⅱ) atom is in a distorted octahedral environment, surrounded by an uncommon symmetrical bidentate chelating carboxylato group and two pairs of bridging chloro ligands. Successive octahedra related by the c-glide of eration share edges to generate a one-dimensional polymeric structure.