The　complex　polymer　[{Cu(2)L(pyca)(H2O)}(n)][ClO4](n).2nH(2),O　[H(2)L　=　N,N＇-bis(2-aminoethyl)　oxamide　Hpyca　=　pyridine-4-carboxylic　acid]　has　been　prepared　and　its　magnetic　properties　and　crystal　structure　determined:　The　crystals　are　monoclinic,　space　group　P2(1)/c,　with　a　=　10.420(2),　b　=　13.118(2),　c　=　14.863(5)　Angstrom,　beta　=　93.05(2)degrees,　and　Z　=　4.　The　structure　consists　of　a　two-dimensional　network　of　copper(II)　ions　bridged　by　the　bis(tridentate)　ligand　L　in　trans　conformation,　and　by　pyridine-4-carboxylate　where　the　carboxylate　group　is　bonded　to　three　different　copper　centres　in　a　novel　manner.　The　repeating　asymmetric　unit　is　a　binuclear　copper(II)　fragment　with　one　of　the　metal　centres　in　an　octahedral　environment　whereas　the　other　is　in　a　distorted　square-based　pyramidal　geometry.　From　magnetic　susceptibility　measurements　the　complex　was　found　to　exhibit　a　strong　antiferromagnetic　coupling　with　J　=　-486　cm(-1)　and　theta　=　-15　K.　due　to　the-efficiency　of　the　oxamidate　and　triatomic　anti-anti　carboxylate　bridges;　in　propagating　antiferromagnetic　exchange　interaction　between　the　copper(II)　ions　which　are　separated　by　about　5.2　and　6.9　Angstrom,　respectively.