To observe the clinical effects of Liuwei Dihuang Pill combined with western medicine in the treatment of mild to moderate Alzheimer's disease (AD), and to explore the mechanism of the treatment of AD with the Liuwei Dihuang pill. Methods:A total of 76 cases of insufficient marrow and deficiency of kidney yin syndrome mild and moderate AD patients who were treated in our hospital from March 2015 to August 2016 were randomly divided into control group and combination group, with 38 cases in each group. The control group was treated with Donepezil Hydrochloride Tablets, and the combined group was given Liuwei Dihuang pill. The treatment effects and the TCM symptoms integral, Mini Mental State Examination (MMSE) score, AD cognitive assessment scale (ADAS-cog) score, ADL score (ADL) changes of 2 groups before and after treatment were compared. Results:The total effective rate of treatment group was significantly higher than the control group (P<0.05); MMSE, ADAS-cog and ADL scores of 2 groups were significantly improved after treatment, and the control group were significantly better than the group (P<0.05); TCM symptoms integral of control group had no significant change (P>0.05), and was significantly reduced in the combination group with significant difference when compared with control group (P<0.05). Conclusion:Liuwei Dihuang pills combined with conventional western medicine in the treatment of mild and moderate AD has significant efficacy, can significantly improve the intelligence and life ability of patients, but also can significantly improve the symptoms of patients, which is worthy of clinical application.