In this paper theoretical calculations of an electroluminescence/photoluminescence-zinc(Ⅱ)chelate complex,[ZnL2](HL = 2-(1H-benzo[d]imidazol-2-yl)-4-bromophenol)were performed based on DFT-and TDDFT-theory level.The molecular geometry,electronic structure,charge transfer character of absorption and emission,effect of the Br group on the absorption/emission property and colors have been analyzed in detail.The results have shown that the charge transfer character of Uv-vis absorptions are of π→π* LLCT.The nature of electroluminescence/photoluminescence is ascribed to π→π* LLCT.The substituted Br group exerts significant effect on the absorption/emission property and colors.The Zn-ligand bonding property is of main ionic interaction based on PDOS/OPDOS and the Mulliken population analyses.It is concluded that the introduction of substituted groups should significantly influence the electroluminescence/photoluminescence-relevant metal chelate complexes with their absorption/emission property and colors being tuned.