tA novel ligand(L), (N,N’-bis(4-methylbenzyl)ethane-1,2-diamine), and its transition metal(Ⅱ) complex, ［ML2(H2O)2］2+·2NO－3(M=CuⅡ, CoⅡ, NiⅡ, ZnⅡ), have been synthesized and characterized by elemental analysis, IR and 1H NMR. The crystal structure of the Cu-L complex was characterized by X-ray single crystal diffraction, and the results showed a regular octahedral structure in which each metal ion is six–coordinated with four nitrogen atoms from two ligands and two oxygen atoms from two water molecules. The interaction of the complex with calf thymus DNA was investigated by UV spectroscopy and fluorescence spectroscopy, and the results suggest that the complex binds to DNA by electrostatic interaction mode. The binding constant(Cu-L, Co-L, Ni-L, Zn-L) was 1.67×103, 2.5×103, 1.35×103 and 9.85×102, respectively.