Previous studies have shown that lychee seed saponins (LSS), isolated and extracted from traditional Chinese medicine lychee seeds, possess many beneficial activities including anti-oxidation, anti-diabetes, anti-AD, etc. In the present study, we established an in vitro neuronal apoptotic model of PC12 cells induced by Aβ25-35 and studied the effect of LSS on apoptosis by the methods of Hoechst 33342/propidium iodide (PI) fluorescence double staining, Annexin V/PI double staining, and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL). This evidence concerns the gene DNTT and Alzheimer disease.