Objective To observe the effect of moxibustion of Baihui（百会GV20） and Shenshu（肾俞 BL 23） on acetylcholine （AOh） content and choline acetyl transferase （CHAT） activity in the brain of aging rats so as to investigate its underlying mechanism in delaying brain aging in the rat. Methods Thirty Wistar rats including 10 young rats （young group） and 20 aged rats that were divided into aging group and moxibustion group evenly, were used in this study. For rats of moxibustion group, moxibustion was applied to Baihui （百会GV20） and Shenshu（肾俞 BL23） for 10 min, once a day, with 5 days being a course of treatment, 8 courses altogether. At the end of the experiments, the rats anesthetized with 6 % chloral hydrate were decapitated for taking brain tissue, then AOh content, CHAT and acetylcholinesterase （ACHE） activity were detected by using high performance liquid chromatography （HPLC）. Results Compared with young rat group, AOh contents of basal ganglia, hippocampus and cerebral cortex tissues in aging group and moxibustion group all decreased significantly （P〈 0.05, 0.01 ）, while compared with aging group, ACh contents in the 3 cerebral regions in moxibustion group all increased considerably （P〈0.01）. In comparison with young group, both CHAT activity and AChE activity of the brain tissue in aging group and moxibustion group lowered significantly （ P 〈 0.05, 0.01 ） ; comparison between aging group and moxibustion group showed that CHAT activity of the later group increased evidently （P〈 0.05） while AChE activity in moxibustion group decreased considerably （P〈0.01）, displaying that moxibustion could potentiate CHAT activity and further lower AChE activity of the brain in aged rats. Conclusion Moxibustion of Baihui（百会GV20） and Shenshu（肾俞 BL23） has effects in raising AOh contents and lowering CHAT and AChE activity, which may contribute to its efficacies in repairing the injured central cholinergic nerve system and delaying the aging
