The current work reports a new Schiff base [N1-benzylidenebenezene-1,2-diamine(L) = C20H16N2] has been synthesized from benzaldehyde (C6H5CHO) and O- aminoaniline (O-C6H4(NH2)2. Metal mixed ligand complexes of the Schiff base were prepared from chloride salts of Zn(II), Cd(II) and Hg(II) in ethanol and 8- hydroxyquinoline(8HQ)(C9H7NO) containing sodium hydroxide. All the complexes were characterized on the basis of their; FT-IR and U.V spectra, melting point, molar conductance, and determination of the percentage of the metal in the complexes by flame (AAS). In the all complexes, (8HQ) behaves as a bidentate ligand as primary ligand through –-OH phenolic group and –N groups of pyridine group. Also, the prepared ligand (L) was bidentate in all complexes coordinating through two nitrogen atoms as a secondary ligand. Mixed ligand complexes of bivalent ions of Zn(II), Cd(II) and Hg(II) of the according to the formula [M(L)( Q)2] in 1:1:2 of molar ratio. The suggest geometry of the complexes appears to be octahedral. The synthesis complexes were tested in vitro for antibacterial activity of ligands and metal complexes to the pathogenic bacteria activity against bacteria (gram +ve) and (gram -ve) has been studied.