To study the effect of Cu2+ and Zn2+ on amyloid-beta peptides (Abeta) aggregation, the morphology, size and cell toxicity of Abeta40 aggregates formed with the metal ions have been observed by the methods including ultraviolet spectroscopy, fluorescence spectroscopy and transmission electron microscopy. The results showed that Cu2+ and Zn2+ can accelerate Abeta40 aggregation, and both changed the morphology and size of Abeta40 aggregates. Zn2+ induced Abeta40 to form fibrous Abeta40 aggregates, while the amorphous and fibrous aggregates were produced by the interaction between Cu2+ and Abeta40. In addition, H2O2 was produced when Abeta40 reduced Cu2+. The relationship between metal ions and Abeta40 aggregates was analyzed, and the function of metal ions in Alzheimer's disease (AD) was illustrated in the research.