Water-soluble Ni(II) and Cu(II) complexes of a flexible Schiff-base ligand have been synthesized, and the Ni(II) complex was characterized by X-ray crystallography. The interactions of the two complexes with calf thymus DNA were investigated by spectroscopic and viscosity measurements in water. The results suggest that the two complexes bind to DNA within the groove. Antioxidant experiments against OHaEuro cent and O (2) (-aEuro cent) show that these two complexes have excellent ability to scavenge O (2) (-aEuro cent) , and the Cu(II) complex exhibits better activity than the Ni(II) complex.