A new 3D copper(I) iodide hybrid, [Cu4I4(TMEDA)2]n(1, TMEDA = N,N,N’,N’-tetramethylethylenediamine), has been solvothermally synthesized and characterized by singlecrystal X-ray diffraction, IR spectroscopy, elemental analysis, powder X-ray diffractions and thermogravimetric analysis. Compound 1 crystallizes in tetragonal space group P42/n with a = b = 11.5663(7) A, c = 9.2456(11) A, V = 1236.87(18) A3, Z = 8, C3H8 CuIN, Mr = 248.54, Dc = 3.507 g/cm3, F(000) = 920, μ(MoKα) = 8.388 mm–1, the final R = 0.0244 and wR = 0.0573 for 1118 observed reflections(I > 2σ(I)). The hybrid framework is built up from cubane-like Cu4I4 cluster and flexible acyclic aliphatic diamine TMEDA, which can be simplified into a twofold interpenetrating dia network. The solid state luminescence spectrum displays a strong yellow emission band at room temperature(Aex = 340 nm, Aem = 530 nm). Results reveal that steric effect of N-substituted methyl groups in TMEDA have obvious influence on the structure and photoluminescent property of compound 1. A new 3D copper (I) iodide hybrid, [Cu4I4 (TMEDA) 2] n (1, TMEDA = N, N, N’N’-tetramethylethylenediamine), has been solvothermally synthesized and characterized by singlecrystal X-ray diffraction, IR Compound 1 crystallizes in a tetragonal space group P42 / n with a = b = 11.5663 (7) A, c = 9.2456 (11) A, V = 1236.87 , Z = 8, C3H8CuIN, Mr = 248.54, Dc = 3.507 g / cm3, F (000) = 920, μ (MoKα) = 8.388 mm-1, the final R = 0.0244 and wR = 0.0573 for 1118 observed reflections ( I> 2σ (I)). The hybrid framework is built up from a cubane-like Cu4I4 cluster and flexible acyclic aliphatic diamine ™ EDA, which can be simplified into a twofold interpenetrating dia network. The solid state luminescence spectrum displays a strong yellow emission band at room temperature (Aex = 340 nm, Aem = 530 nm). Results reveal that steric effect of N-substituted methyl groups in TMEDA have obvious influence on the structure and p hotoluminescent property of compound 1.