A novel cadmium complexes of {［Cd(H2biim)2(SO4)］·3H2O}n (1) (H2biim=2,2’-biimidazole) was synthesized by hydrothermal reaction of 3CdSO4·8H2O and 2,2’-biimidazole ligand. The complex was built up by ［Cd(H2biim)2］2+ units bridged sequentially by SO2-4 anions to form 1D zigzag chains parallel to the c-axis. The H2biim ligands were attached to the 1D chain as branches of the chain by coordinating to Cd2+ at two sides of the chain. The chains were held together by π—π interaction and O—H…O interactions, thus yielding a 3D extended supramolecular network. The responses of symmetric stretching vibration of SO2-4, N—C single bond, NC double bond and anti-symmetric stretching vibration of N—C single bond were detected in 2D IR correlation spectra under thermal perturbation. The complex exhibited strong blue emission peak at 498 nm (λex=397 nm) that can be assigned to a ligand-to-metal charge-transfer (LMCT) band.