A new Cd~Ⅱ coordination complex,namely [Cd(iba)_2]_n(1),was prepared by the hydrothermal reaction of Cd(NO_3)_2·4H_2O with 4-imidazol-1-yl-benzoic acid(Hiba). Single-crystal X-ray diffraction analysis shows that compound 1 crystallizes in monoclinic system,space group Cc with a = 11.403(4),b = 30.480(9),c = 7.732(3) ?,β = 130.189(4)o,V = 2503.0(1) ?~3,Z = 4,C_(22)H_(18)CdN_4O_4,Mr = 514.80,Dc = 1.666 g/cm~3,F(000) = 1032 and μ(Mo Kα) = 1.101 mm-1. The final R and wR are 0.0573 and 0.1823 for 4421 observed reflections with I > 2σ(I). Each iba-ligand coordinates in a bidentate fashion,connecting the Cd(Ⅱ) atoms to form a 2D wave-shape layer structure,which can be simplified as a four-connected topological net. Interestingly,the 2D layers are further extended into a 3-fold interpenetrating 3D architecture. Compound 1 displays an emissive maximum at 455 nm in the solid state at room temperature and a response of the second harmonic generation(SHG) activity is approximately 0.8 times that of KDP. A new Cd ~ Ⅱ coordination complex, namely [Cd (iba) _2] _n (1), was prepared by the hydrothermal reaction of Cd (NO_3) _2 · 4H_2O with 4-imidazol- 1-yl-benzoic acid (Hiba). Single-crystal X-ray diffraction analysis shows that compound 1 crystallizes in a monoclinic system with space group Cc with a = 11.403 (4), b = 30.480 (9), c = 7.732 , V = 2503.0 (1)? ~ 3, Z = 4, C 22 H 18 CdN 4 O 4, Mr = 514.80, Dc = 1.666 g / cm 3, F 000 000 = 1032 and μ Mo Kα, = 1.101 mm-1. The final R and wR are 0.0573 and 0.1823 for 4421 observed reflections with I> 2σ (I). Each iba-ligand coordinates in a bidentate fashion, connecting the Cd (II) atoms to form a 2D wave- shape layer structure, which can be simplified as a four-connected topological net. Interestingly, the 2D layers are further extended into a 3-fold interpenetrating 3D architecture. Compound 1 displays an emissive maximum at 455 nm in the solid state at room temperature and a response of the second harmonic generation (SHG) activity is approximately 0.8 tim es that of KDP.