A new mononuclear CuⅡ complex of DACO [Cu(DACO)2(SCN)]·(SCN)·2H2O ( 1) was prepared by introducing a co-ligand SCN-anion. The crystal structure of 1 was determined by X-ray diffraction analysis. The crystallographic data are: m onoclinic, P21/n, a=0.728 5(4) nm, b=2.479 0(15) nm, c=1.069 7(6) nm, The CuⅡ atom takes the square-pyramidal coordinatio n geometry. The SCN-anions adopt both monodentate coordination and uncoordinate d forms in the crystal. The coordinated cation, SCN-counter anion and the latti ce water molecules are further linked through hydrogen bonds to form a one-dimen sional chain motif. The spectral and thermal properties of 1 were studied. CCDC: 243104.