A method for preventing or treating a brain nervous disease includes administering to a subject in need thereof a therapeutically effective amount of a carbon nanotube, wherein the nervous disease is a brain disease or a traumatic central nervous system injury. The composition of the present invention enables patients to recover from physical damage to the brain, exhibits superior efficacy for inhibiting the onset of Parkinson's disease and strokes in animal models for Parkinson's disease and strokes, and the cytotoxic effects of beta amyloid in beta amyloid toxicity tests. Therefore, the composition of the present invention can be effectively used in the preparation of medicine for protecting cranial nerves, therapeutic agents for preventing or treating brain disease, or therapeutic agents for treating traumatic injuries to the central nervous system.