The DNA nuclease-like activity of a water soluble manganese corrole 5,10,15-tris(N-methyl-4-pyridyl)- corrolatomanganese(Ⅲ) (MnⅢTMPyC) has been investigated.MnⅢTMPyC may bind strongly to DNA via outside groove binding mode as indicated by absorption spectra,viscosity measurements and CD spectra.MnⅢTMPyC exhibited excellent catalytic activity in the DNA oxidative cleavage in the presence of hydroperoxide.