The present invention relates to a method of inducing neuro-regeneration comprising administering a MEK 1/2 inhibitor to a patient in need thereof. In the present invention, the MEK1/2 inhibitor induces neuro-regeneration by differentiating neural stem cells into neurons, by protecting neural stem cells and neurons against cytotoxicity of amyloid-betas, or by both of the above. Also, the present invention relates to a method of protecting neurons against neuronal loss or damage comprising administering a MEK1/2 inhibitor. In addition, this invention relates to a method of preventing or treating neurodegenerative disease due to neuronal loss or damage for patients in need thereof comprising administering a MEK 1/2 inhibitor.