The hydrogen-bonding copper complex [Cu(mal)(phen)(H2O)]2·3H2O(mal=malonate;phen=1,10-phenanthroline)was synthesized and characterized byelementary analysis,IR and TG-DTA.Single crystal X-ray diffraction analysis indicates that the compound crystallizes in a triclinic system,space group Pī,the cell parameters a=11.771(2)?,b=12.527(3)?,c=11.582(2)?;a=105.49(3)°,β=109.27(3)°,γ=92.13(3)°,V=1539(5)A3,Z=2,F(000)=794,S=1.087,R=0.0486,wR=0.1220.The copper atom is five-coordinated in a distorted square pyramidal environment to two oxygen atoms of malonate,two nitrogen atoms of 1,10-phenanthroline and a water molecule.Strong hydrogen bonds between coordinated water and oxygen atoms of malonate ligands build H-bonding tetramers.Weak hydrogen bonds link these tetramers by crystal lattice water,forming two-dimensional supramolecular network.