A　new　Zn(II)　phosphonate　complex,　[Zn3(PhPO3)　2(PhPO3H)2(Phen)2]n　(Phen=1,10-phenanthroline),　has　been　synthesized　and　structurally　determined　by　X-ray　single-crystal　diffraction.　The　complex　crystallizes　in　the　monoclinic　system,　space　group　Cllc　with　a=14.997(3),　b=18.108(4),　c=17.237(3)　Å,　β　=　96.61(3)°,　V　=　4649.9(16)　Å3,　Z　=　4,C　48H38N4O12P4Zn　3,　Mr=1182.87,　Dc　=　1.690　g/cm3,　=1.743　mm-1,　F(000)　=　2400,　the　final　=　0.0363　and　wR=0.0963.　In　the　structure,　the　connectivity　between　two　5-coordinated　Zn(II)　atoms　and　four　phosphonates　as　well　as　two　Phen　ligands　form　a　Zn2(PhPO　3H)2(PhPO3)2(Phen)2　unit,　and　such　a　neighboring　unit　is　bridged　by　4-coordinated　Zn(II)　to　give　rise　to　a　ID　chain　along　the　c　axis.　The　φ-φ　stacking　interactions　between　Phen　rings　assemble　adjacent　chains　packed　together　to　form　a　3D　supermolecular　architecture.