Objective To explore the effect of exogeneous NGF on the expression of ChAT-IR and SP in the central nervous system of demential senile mice.Method Morris water labyrinth was adopted to test the spatial learning and memory function of mice.Immunohistochemical technique was used to observe the expression of ChaT-IR and SP in dementialy senile mice before and after NGF administration.Result The exogeneous NGF improved the spatial learning and memory function of senile mice and expression of ChAT-IR in related area in the brain.SP expression significantly increased in comparison with that before administration(P<0.01).Conclusion Exogeneous NGF can improve the intelligence of aged mice and significantly increase the expression of ChAT-IR and SP in related area in the brain.The exogeneous NGF may exert protective,supportive and repairing effects on neurons.