Four nickel bis(dithiolene) complexes with different substituent groups were synthesized and characterized. The physical and chemical properties of the complexes were systematically studied. The UV-Vis-NIR spectra showed strong and broad absorptions in the NIR region (700～1100 nm). The substituent effect and solvent effect of the complexes were investigated. The electron donating substituent results in the red-shifted absorption band, while the electron withdrawing substituent results in the hypsochromic-shifted absorption band. The red-shifted absorption band was observed as increasing the polarity of the solvent. The electrochemical properties were investigated by both of cyclic voltammetry/differential pulse voltammetry (CV/DPV). Furthermore, the HOMO and LUMO energy levels of the dyes were obtained by Density Functional Theory (DFT) calculations. TG studies revealed the good thermal stability of the complexes.