The mechanism for interactions of the 6-benzyl-amino-purine and its Co2+, Ni2+ complexes with DNA was studied by UV and fluorescence spectra using ethidium bromide (EB) as probe molecule. When pH=7.4, the action of 6-benzyl-amino-purine-Co2+ and DNA was electrostatic effect and certain kind of intercalation action; when pH=9.86, the action of the two was electrostatic effect; when pH=2.85 , the action of 6-benzyl-amino-purine-Ni2+ and DNA was both electrostatic and intercalation action. But when pH=7.4, 6-benzyl-amino-purine hardly influenced the intercalation action of EB and DNA, the action of 6-benzyl-amino-purine and DNA was electrostatic action.
