Secondary structures such as alpha-helix and beta-sheet are the major structural motifs within the three-dimensional geometry of proteins. Therefore, structure transitions from beta-sheet to alpha-helix not only can serve as an effective strategy for the therapy of neurological diseases through the inhibition of -sheet aggregation but also extend the application of alpha-helix fibrils in biomedicine. Herein, we present a charge-induced secondary structure transition of amyloid-derived dipeptide assemblies from beta-sheet to alpha-helix. We unravel that the electrostatic (charge) repulsion between the C-terminal charges of the dipeptide molecules are responsible for the conversion of the secondary structure. This finding provides a new perspective to understanding the secondary structure formation and transformation in the supramolecular organization and life activity.