A new series of water-soluble transition mixed liga nd complexes of Co (II) and Ni (II) have been synth esized from the Schiff base ligand (HL) derived from morpholine derivatives as a primary ligand with 1,10-phenonth roline (X) and 2,2’-bipyridine (Y) as co-ligands. Structural f eatures were obtained from their elemental analyses , magnetic susceptibility, molar conductance, mass, FT-IR, UV– Vis., spectral studies. The data show that all the mixed ligand complexes have composition of [MLX]4H 2 O and [MLY]4H 2 O. The spectral data showed octahedral geometry around the central metal ion. The redox behavior of metal complexes was studied by cyclic voltammetry. The binding strength and binding mode of complexes with HS DNA (Herring Sperm) have been investigated by absorption titration and viscosity measurement stud ies. The results show a considerable interaction be tween complexes and HS-DNA. The nuclease activities of th e complexes have shown that they cleave calf thymus DNA under aerobic condition and in the presence of H 2 O 2 through redox chemistry. The in vitro biological a nd antioxidant activities have shown that the mixed li gand complexes have higher potent activities than t he free ligand.