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 orthorhombic,space group Aba2 with a=1.747 6(3) nm,b=1.933 6(4) nm,c=0.692 75(13) nm,V=2.340 9(8) nm3,Mr=700.96,Dc=1.989 g·cm-3,μ(Mo Kα) =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(I>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.CCDC:692298.