Abstract: OBJECTIVE To explore the expression of serum microRNAs (miRNAs) in patients with mild and moderate Alzheimer's disease and the effect of modified Yam Pills on it. METHODS The literature of peripheral blood miRNAs in AD patients was retrieved in Pubmed and China National Knowledge Internet database. The miRNAs with consistent expression in multiple literatures were selected for the study. Totally 56 patients with mild and moderate Alzheimer's disease were treated with modified Yam Pills of 15 mL each time， twice a day for 12 weeks. Another 56 cases with normal cognitive function were collected as control group. The serum miRNAs levels of AD patients before and after treatment and control group were measured by fluorescence quantitative PCR. RESULTS Compared with the control group， the expression of serum miR-107， miR-29a， miR-29b， miR-181c， miR-125b， miR-135a and miR-342-3p were significantly decreased in the AD group， and the expression of miR-146a was significantly increased (P<0.01). Compared with those before treatment， the expression of serum miR-107， miR-29a， miR-29b， miR-181c， miR-125b and miR-342-3p were significantly increased after treatment in the AD group (P<0.05， P<0.01)， and the expression of miR-146a was significantly decreased (P<0.01). CONCLUSION Detecting the expression of serum miR-107， miR-29a， miR-29b， miR-181c， miR-125b， miR-135a， miR-342-3p and miR-146a may be helpful to the early diagnosis of AD patients. Modified Yam Pills may play a role in the treatment of AD by regulating the levels of serum miR-107， miR-29a， miR-29b， miR-181c， miR-125b， miR-342-3p and miR-146a in AD patients.