A　new　neutral　dinuclear　copper(I)　complex　bearing　N-ligands　2,　9-di-n-butyl-1,　10-phenanthroline　(dnbp),　[CuI(dnbp)]2,　was　synthesized　by　the　reaction　of　CuI　and　dnbp　in　tetrahydrofuran　solution.　The　complex　was　characterized　by　single　crystal　X-ray　diffraction,　1H　NMR,　UV-Vis　spectra,　and　photoluminescence　spectra.　The　results　show　that　the　complex　consists　of　a　distorted　tetrahedral　Cu2I2　core,　in　which　two　copper(I)　ions　are　linked　by　two　iodo-bridges,　and　two　dnbps　chelated　with　copper(I)　ions,　respectively.　The　complex　shows　small　angle　of　I-Cu-I　(106.08°),　and　long　Cu⋯Cu　distance　(0.3149　nm)　which　suggests　a　negligible　interaction　between　two　copper　ions.　These　features　can　be　attributed　to　the　bulk　steric　hindrance　of　dnbp　ligands.　The　complex　belongs　to　trigonal　system　with　space　group　of　R-3　and　cell　dimensions　a=4.40414(11)　nm,　b=4.40414(11)　nm,　c=1.085　92(4)　nm,　γ=120°,　V=18.2411(9)　nm3.　The　complex　has　a　low-energy　absorption　band　ranging　from　350　nm　to　500　nm　in　dichloromethane　solution,　which　can　be　assigned　to　the　metal-to-ligand　charge　transfer　(MLCT)　transitions.　At　room　temperature,　the　complex　in　the　solid　state　exhibits　red　photoluminescence　with　a　broad　emission　band　from　550　nm　to　800　nm　and　the　maximum　peak　at　653　nm　under　excitation　at　365　nm.　The　emission　lifetime　of　the　complex　is　3.1　μs,　and　photoluminescence　quantum　yield　is　0.013.　The　luminescence　mechanism　of　the　complex　belongs　to　the　phosphorescent　emission　at　the　exited　state,　which　is　formed　by　electron　charge　transition　from　cuprous　ion　and　halogen　to　ligand　dnbps.　At　10　K,　the　maximum　emission　peak　shifts　to　645　nm　with　narrow　spectral　band　width.