Abstract: Using reactants of copper chloride and correspoinding 2-substituted benzimidazole in organic solvent of acetone or 2-butanone, Copper complexes of 2-phenyl-benzimidazole (BIm_a) and 1-(p-methoxybenzul)-2- (p-methoxyphenzyl)-benzimidazole (BIm_b) were synthesized under microwave irradiation with the yield of 80% and 75% respectively. The melting point of BIm_a or BIm_b copper complex was measured as 145℃ and 225 ℃ separately. Methods of equipment analyses, such as IR, XRD, UV, DSC / TG, SEM, melting point, were employed to characterize the properties and structures of the complexes. Coordination reaction was confirmed from measurements of molar conductivity, infrared spectra, and UV spectra. The crystal was determined as monoclinic from XRD and SEM characterization. The coordination number was determined as 1 and 0.5 for copper complex of BIm_a and BIm_b.