Abstract A Tetraaza Macrocylic Ligand (H 2L) and its complexes, [Cd(H 2L)(OH 2) 2](NO 3) 2·1/2OH 2 (I), [Co(H 2L)(OH 2)](NO 3) 2·1/2OH 2 (II), [Cu(H 2L)(NO 3) 2]·3/2OH 2 (III) and [Ni(H 2L)(NO 3)(OH 2)]NO 3·OH 2 (IV), have been synthesized and characterized on the basis of elemental analysis, molar conductivity, 1H NMR, UV–vis, FT-IR and mass spectroscopy. All results confirm that the prepared compounds have 1:1 metal-to-ligand stoichiometry, octahedral configuration and the ligand behaves as a neutral tetradendate towards the metal ions. [CdL(OH 2) 2] (V), [CoL(OH 2) 2] (VI), [CuL(OH 2) 2] (VII) and [Ni(H 2L)(NO 3) 2] (VIII) were synthesized pyrolytically in solid state from corresponding compounds (I–IV). Analytical results of complexes (V–VIII) show that the ligand behaves either as a neutral tetradendate or dianionic tetradentate ligand towards the metal ions. The binding of H 2L and its copper complex (III) to DNA has been investigated by ultraviolet absorption spectroscopy. The experiments indicate that H 2L and its copper complex (III) can bind to DNA through an intercalative mode. The H 2L and its copper complex (III) exhibited anti-tumor activity against Ehrlich Acites Carcinoma (E.A.C) at the concentration of 100 μg/ml.