Abstract: Cu^2＋ and Zn^2＋ ions were reported to be able to induce Aβ aggregation at nearly physiological concentrations in vitro and related to the pathogenesis of Alzheimer’s disease. The smaller peptides including Aβ(1-28) was chosen as the target peptide, which helped define the nature of the interaction of the full length peptide. And we studied the influences of the different conditions including the pH, temperature, apparatus conditions, concentration on the impact of complex of Zn^2＋, Cu^2＋ and Aβ. Our findings by the studies of ESI-MS revealed the stoichiometry of 1:1 for the peptide-metal complexes, and to bind up to four cations upon increasing the metal concentration.