Objective To explore the effect and mechanism of action of NGF on the intelligence in demential senile mice. Method Fourty five 18 month-old ICR mice were selected and randomly divided into two groups. The expression of choline acetyltransterase (ChAT-IR) and nerve growth factor (NGF) in various areas of the brain was assyed. Mirro-labyrinth experiment was conducted before and after administration of exogenous NGF. ChAT-IR activity and Anti-NGF immunohistochemical examination were performed. Result The intelligence of senile mice were changed. Significant changes of ChAT-IR and NGF expression in areas in the brain and in Mirro labyrinthian experiment occurred (P < 0.05) in the cytidine diphosphocholine group. Exogenous NGF treatment group showed significantly increased staining of ChAT-IR and anti-NGF, and changes in the labyrinthian experiment (P <0.01). Conclusion Exogeneous NGF may improve the intelligence of aged mice and increase ChAT-IR and anti-NGF expression in various areas in the brain, and exert protective, supportive and reparative effects on neurons.