A complex of dihydromyricetin-Zn(DMY-Zn)was prepared firstly,the interaction of DMY-Zn complex with DNA was investigated by using fluorescence titration that ethidium bromide(EB) as a fluorescence probe and viscosity measurements.The results indicated that DMY and Zn2+ ions are easy to form complexes which compositions were tested as [C15H10O8Zn]?2H2O by characterization using UV-Vis,IR spectroscopy,elemental analysis and thermal gravimetric analysis(TG-DTA).With the strong interaction with DNA,the DMY-Zn complex can compete with the strong intercalator ethidium bromide to intercalate into the stacked base pairs through the intercalation which the Stern-Volmer quenching constant Ksq is equal to 1.01.