A　new　Zn(II)　phosphonate　complex,　[Zn-3(PhPO3)(2)(PhPO3H)(2)(Phen)(2)](n)　(Phen　=　1,10-phenanthroline),　has　been　synthesized　and　structurally　determined　by　X-ray　single-crystal　diffraction.　ne　complex　crystallizes　in　the　monoclinic　system,　space　group　C2/c　with　a　=　14.997(3),　b　=　18.108(4),　c　=　17.237(3)　angstrom,　beta　=　96.61(3)degrees,　V　=　4649.9(16)　angstrom(3),　Z　=　4,　C48H38N4O12P4Zn3,　M-r　=　1182.87,　D-c　=　1.690　g/cm(3),　mu　=　1.743　mm(-1),　F(000)　=　2400,　the　final　R　=　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　Zn-2(PhPO3H)(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　pi-pi　stacking　interactions　between　Phen　rings　assemble　adjacent　chains　packed　together　to　form　a　3D　supermolecular　architecture.