Aim: observe the effect of acupuncture at shenmen (HT 7) in activating the brain functional region of patients with Alzheimer disease (AD) with brain functional, MRI (fMRI), and probe into the impersonal basis of acupuncture for treating AD. Methods: Six patients with mild to moderate AD admitted in Xuanwu Hospital between March 2004 and August 2004 were treated with electroacupuncture at shenmen (HT 7). The data of fMRI were collected on 1.5 T MRI systems and analyzed by Statistical Parametric Mapping software to obtain the activation maps of brain function. Results: The major role of acupuncture at shenmen (HT 7) was to activate the functional area of contralateral cortex, including left middle frontal gyrus, superior temporal gyrus transverse temporal gyrus, precentral gyrus and postcentral gyrus, thalamus, and putamen. In addition, there was other activation in right middle frontal gyrus and superior temporal gyrus. Conclusion: The different areas of cerebral cortices activated by acupuncture at shenmen (HT 7) have close correlation with sensory-motor central nervous system and cognitive function, indicating the objective foundation that acupuncture at shenmen (HT 7) can play an important role in treatment of senile dementia.