Objective To study the effect of ?-scretase substrate-base peptide(BACEsp) on cellular model of Alzheimer's disease(AD).Methods The cellular model of AD established with neuroblastoma cell SK-N-SH induced by amyloid precursor protein(APP) was infected with the supernatants including recombinant retrovirus pLXSN-BACEsp.MTT assay was used to test cell viability and immunocytochemistry was used to observe APP expresion in cells before and after BACEsp treatment.Results Cell viability and APP expression in the cells that had been first infected by recombinant retrovirus pLXSN-BACEsp were apparently higher than those only transfected by APP and last infected by recombinant retrovirus pLXSN-BACEsp.Conclusion BACEsp has an obviously protective effect on APP-induced neuron toxicity of cellular model of AD.