Objectives: This experiment was designed to investigate the effect of the InSamYangYoung-tang(Renshenyangrongtang) extract on Aβ-induced AD model. Methods: The effects of the InSamYangYoung-tang(Renshenyangrongtang) extract on neural damages of cultured PC12 cells induced by Aβ were investigated. The effects of the InSamYangYoung-tang(Renshenyangrongtang) extract on neural damages of hippocampal and cortical neurons in the mouse induced by β-amyloid were investigated. Results: 1. Aβ treatment into neuronal cells activated cell death pathway when analyzed by MTT assay and by histological analysis. Then InSamYangYoung-tang(Renshenyangrongtang) treatment improved cell survival to a similar level as in normal group. 2. Aβ treatment increased caspase 3 protein levels but decreased phospho-Erk1/2 in neuronal cells. InSamYangYoung-tang (Renshenyangrongtang) treatment reversed the production levels of two proteins close to those in normal group. 3. Aβ treatment induced the atrophy of neuronal cells in terms of neuronal processes and cell body shrinkage, but InSamYangYoung-tang(Renshenyangrongtang) greatly improved their morphology. 4. Neuroprotective activity, as observed in InSamYangYoung-tang(Renshenyangrongtang)-treated groups, was similarly observed in cells treated with galantamine which was used as a positive control. Moreover, overall recovery pattern by InSamYangYoung-tang(Renshenyangrongtang) was similar between cultured PC12 cells and in vivo hippocampal and cerebral cortical neurons in the mouse brain. Conclusions: This experiment shows that the InSamYangYoung-tang(Renshenyangrongtang) may play a protective role in neural tissues damaged by cytotoxic substances. Since neuronal damage seen in degenerative brains such as AD are largely unknown, the current data may provide possible insight into therapeutic strategies for AD treatments. InSamYangYoung-tang(Renshenyangrongtang) might be effective for the treatment of AD. Investigation into the clinical use of the InSamYangYoung-tang(Renshenyangrongtang) for AD is suggested for future research.