A Tetraaza Macrocylic Ligand (H 2 L) and its complexes, [Cd(H 2 L)(OH 2 ) 2 ](NO 3 ) 2 ·1/2OH 2 (I), [Co(H 2 L)(OH 2 )](NO 3 ) 2 ·1/2OH 2 (II), [Cu(H 2 L)(NO 3 ) 2 ]·3/2OH 2 (III) and [Ni(H 2 L)(NO 3 )(OH 2 )]NO 3 ·OH 2 (IV), have been synthesized and characterized on the basis of elemental analysis, molar conductivity, 1 H 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 2 L)(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 2 L and its copper complex (III) to DNA has been investigated by ultraviolet absorption spectroscopy. The experiments indicate that H 2 L and its copper complex (III) can bind to DNA through an intercalative mode. The H 2 L and its copper complex (III) exhibited anti-tumor activity against Ehrlich Acites Carcinoma (E.A.C) at the concentration of 100μg/ml.