Three new copper(II) complexes, viz. [Cu(II)(1-amidino-O-2-methoxyethylurea) 2 ](ClO 4 ) 2 ·H 2 O (1), [Cu(II)(1-amidino-O-2-ethoxyethylurea) 2 ](ClO 4 ) 2 ·2/3H 2 O (2) and [Cu(II)(1-amidino-O-2-butoxyethylurea) 2 ](ClO 4 ) 2 (3), have been synthesized and characterized by means of analytical and spectroscopic techniques. The single crystal X-ray structure of complex 2 and X-ray powder diffraction studies on complexes 1 and 3 show that they crystallize in the triclinic system. The asymmetric unit of complex 2 contains one and half [Cu(II)(1-amidino-O-2-ethoxyethylurea) 2 ] 2+ units, three perchlorate anions to balance the charge and a water molecule. The binding of these complexes with CT-DNA suggested that these complexes interact with CT-DNA by partial or non-intercalative modes.