A　novel　coordination　polymer　{[Cu(en)(2)][Ag2I4]}(n)　(en　=　ethylenediamine)　was　synthesized　by　the　reaction　of　NaAgI2　and　Cu(en)(2)(NO3)(2)(.)2H(2)O　at　room　temperature　with　pH　=　6.0,　and　the　structure　was　characterized　by　X-ray　single-crystal　diffraction.　It　crystallizes　in　monoclinic,　space　group　C2/m,　with　a=10.646(2),　b　=　13.304(3),　c　=　6.8445(14)　angstrom,　beta　=　118.95(3)degrees,　C4H16N4CuAg2I4,　M-r　=　907.10,　V　=　848.3(4)　angstrom(3),　Z　=　2,　D-c　=　3.551　g/cm(3),　F(000)　=　806,　mu(MoK　alpha)　=　10.787　mm(-1),　the　final　R-1　=　0.0256　and　wR(2)=　0.0654　for　900　observed　reflections　with　1　＞　2　sigma(1).　According　to　structural　analysis,　the　title　compound　consists　of　template　cation　[Cu(en)(2)](2+)　and　inorganic　chain　[Ag2I4](n)(2-).　The　polymeric　negative　chain　[Ag2I4](n)(2-)　is　built　up　from　pairs　of　AgI4　tetrahedron　by　sharing　one　edge.　Through　N-(HI)-I-...　hydrogen-bonding　interactions,　the　whole　structure　represents　a　quasi-two　dimensional　arrangement.　Electrostatic　attraction　exists　between　organic　cations　and　inorganic　chains,　leading　to　a　so-called　organic-inorganic　hybrid　structure.