DNA binding and DNA cleavage characteristics of synthesized mixed ligand copper(II) complexes of the type [Cu(HL)2Cl2](1), [Cu(HL)(bipy)Cl2](2), [Cu(HL) (phen)Cl2](3), [Cu(HL)2Br2](4), [Cu(HL) (bipy)Br2](5), [Cu(HL)(phen)Br2](6) (Where, L= 2- (methylsulfanyl)-N-(1H-pyrrole-2-ylmethylidene) aniline, bipy= 2,2’-Bipyridine, Phen= 1,10- Phenanthroline) have been investigated in detail. DNA binding properties of copper(II) complexes have been investigated by electronic absorption spectroscopy. Results suggest that the copper (II) complexes were bound to DNA by an intercalation binding mode. The in vitro antimicrobial activities of the synthesised compounds have been tested against the bacteria Escherichia Coli and the fungi Aspergillus niger by using disc agar diffusion method. The minimum inhibitory concentration (MIC) value against the growth of the above microorganism is much larger for mixed ligand copper(II) complexes. The cleavage activities of complexes (1), (2), (3), (4), (5) and (6) were carried out on double-stranded pUC19 DNA using gel electrophoresis. The complexes show better nuclease activity for mixed ligand copper(II) complexes.