Abstract: Alzheimer's disease (AD) is one of the most common neurodegenerative diseases that the death of neuron cells causes severe memory loss and cognitive decline. The accumulation and aggregation of amyloid beta protein (Aβ) is closely related to AD pathogenesis. Therefore, it is meaningful to develop novel suppressors that can effectively suppress Aβ aggregation. Minichaperone derived from apical domain of E. coli chaperone GroEL (residues 191-345) is a potential suppressor for Aβ aggregation, which can bind target proteins through hydrophobic interactions with good biocompatibility. A series of biochemical and biophysical experiments (thioflavin T (ThT) fluorescence spectra, transmission electron microscopy (TEM), gel filtration chromatography analysis (ana-SEC), and cytotoxicity assay) were performed to investigate the interaction between minichaperone and Aβ₄₂. Meanwhile, the effects of polyphenol suppressors such as curcumin, epigallocatechin gallate (EGCG) and quercetin were also studied. Minichaperone can effectively suppress the formation of Aβ₄₂ fibrils. The aggregation suppression is achieved by reducing the aggregation level of Aβ₄₂ and shifting the on-pathway aggregates to off-pathway aggregates. The molecular weights of aggregates and fibrils morphology change significantly. Compared to the control group, addition of the minichaperone decreases in situ ThT fluorescence of Aβ₄₂ solution up to 72% after 16 h of aging, shortens the length of Aβ42 fibril from >200 nm to < 50 nm after 24 h of aging, and increases SH-SY5Y cell viability by more than 20%. Therefore, minichaperone presents a promising therapeutic application as a suppressor of Aβ aggregation by prevention of amyloid fibril formation and reduction of Aβ cytotoxicity.