Five taxane diterpenoids derived from the 95% ethanol extract of Taxus chinensis were tested for the inhibitory activities on amyloid-beta (Aβ) peptide aggregation. Using thioflavin-T fluorescence assay, sciadopitysin was found to exhibit the most potency against Aβ aggregation and the formation of fibrils. Further cellular assay indicated that sciadopitysin increased the cell viability of SH-SY5Y cell and demonstrated neuroprotection against Aβ protein-induced insult in primary cortical neurons. According to the authors' best knowledge, this is the first report that sciadopitysin can inhibit the Aβ aggregation and reduce Aβ-induced toxicity in the primary cortical neurons.