Objective:To explore the mechanism of embedding catgut acupoint (ECA) to treat the AD patients by the brain functional magnetic image(fMRI).Methods:26 patients suffering from mild to moderate AIzheimers disease (AD) were divided into the embedding catgut acupoint group(ECAG)and the control group (CG) by the paired method.Every group had 13 cases.The subjects in ECAG were embedded catgut in Shenmen (HT7),Fengiong(ST40),Taixi (KI3) and Zusanli (ST36)acupoints.The subjects in CG were operated on the same acupoints by the empty lumber puncture needle,which the chromic suture was not put into.The patients were treated once every month and 6 times therapy was given altogether.All patients were evaluated by the neuropsychology scales (Mini-Mental State Examination,MMSE,AIzhemers Disease Assessment Scale-Cognitive section,ADAS-Cog) a week before and after treatment,Furthermore,all subjects were detected by fMRI to obtain the data of the cerebral blood and oxygen.The change of the scales and data of fMRI were correlatively analyzed by SPM.Results:(1) Compared with the pretherapy scores for ECAG patients,the post-treatment scores of MMSE significantly increased (P<0.01) and the scores of ADARS-cog significantly decreased (P<0.01).The scores of MMSE significantly decreased (P<0.01)and the scores of ADARS-cog increased (P<0.05) for CG patients.The scores of MMSE for ECAG were significantly higher than CG patients (P<0.01) and the scores of ADARS-cog for ECAG patients were significantly lower than CG patients after the therapy (P<0.05).(2) After 6 month treatment,the comparison of the significantly activated region between the ECAG and the CG:the frontal lobe (the middle frontal gyrus,the inferior frontal gyrus,the medial frontal gyrus),the temporal lobe (the superior temporal gyrus,the middle temporal gyrus,the transverse temporal gyrus,the fusiform gyrus),the limbic system (the hippocampal gyrum,the cingulated gyrus,the insula),the parietal lobe (the inferior parietal lobule,the postcentral gyrus),the cerebellum,the brainstem and some basal nucleus were activated.The correlative analysis between neuropsychology scores and fMRI in ECAG,The activated region related with the MMSE:the inferior frontal gyrus,the middle frontal gyrus,the superior frontal gyrus,the transverse temporal gyrus on the left cerebrum and the superior frontal gyrus,the middle frontal gyrus,the precentral gyrus,the hippocampal gyrum,the postcentral gyrus,the paracentral lobule on the right side.The activated region related with the ADARS-cog:the inferior frontal gyrus,the middle frontal gyrus,the fusiform gyrus,the inferior temporal gyrus on the lett cerebrum and the superior frontal gyrus,the middle frontal gyrus,the precentrai gyrus,the fusiform gyrus,the transverse temporal gyrus,the postcentral gyrus,the middle occipital gyrus on the right side.Conclusions:The ECA could improve cognitive ability in AD patients.It is a possible mechanism that the ECA activated cognitive region of the frontal lobe,the temporal lobe and the cerebellum.