In the first section of this thesis, ligand 4-Nitro Phenylcinamide (4-NO 2 pcyd) has been synthesized and structurally characterized by elemental analysis (C, H, N), FT-IR,UV-Vis, NMR resonance signals, and single crystal X-ray diffractometry. In the next step, Complexes of Nickel, Cobalt, Zinc and Cadmium with this new ligand have been synthesized and characterize by elemental analysis (C, H, N), FT-IR, Mass and single crystal X-ray diffractometry. This project, continued in two parts. In the first part, Metal complexes of the type [Ni(HIm) 4 (4-NO 2 pcyd) 2 ], 1 , [Ni(bpy) 2 (4-NO 2 pcyd) 2 ], 2, [Ni(phen) 2 (4-NO 2 pcyd) 2 ], 3 , (HIm = Imidazole, bpy = 2,2?-bipyridine, phen = 1,10-phenanthroline, 4-NO 2 pcyd = 4-nitro phenylcyanamide) have been studied. The interaction of 1-3 with calf thymus DNA and bovine serum albumin was investigated using UV-Visible and fluorescence spectrophotometric methods. The photo induced cleavage studies show that the complexes possess photonuclease property against pUC19 DNA under UV–Visible irradiation. The in vitro antimicrobial activity and cytotoxic potential of all the complexes were examined. In the second part, Metal complexes of the type[Co(phen) 2 (4-NO 2 pcyd) 2 ],1, [Zn(phen) 2 (4-NO 2 pcyd) 2 ], 2, [Cd(phen) 2 (4-NO 2 pcyd) 2 ], 3, have been studied. The synthesis, characterization and the biological activities of complexes 1-3 have been investigated. The geometries of complexes 1-3 were confirmed by single crystal X-ray crystallography. The interactions of complexes 1-3 with human serum albumin (HSA) were studied using fluorescence and circular dichroism spectroscopy. The thermodynamic studies have shown the reaction for the binding of complexes 1-3 with HSA is hydrophobic (?H0 ? 0 and ?S0 0). The in vitro cytotoxic potential of complexes 1-3 and their complexes with HSA were examined. The complexes 1-3 with HSA enhance about 3-fold cytotoxicity in cancer cells lines.