Objective:To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on the cognition of patients with mild cognitive impairment (MCI).Methods:The PubMed, Cochrane Library, Embase, Web of Science, CNKI, Wanfang, and VIP databases were searched for randomized controlled trials of rTMS treating MCI patients before March 2019. After screening the literature, extracting the data and two independent reviewers evaluating the quality of the included studies, the meta-analysis was conducted using version 5.3 of the RevMan software.Results:Nine studies covering 368 patients were included. The pooled results showed that compared with sham stimulation, rTMS treatment could effectively improve the cognitive ability (assessed using the Montreal instrument), episodic memory, verbal fluency and the amplitude of MCI patients′ P300 signals. P300 latency was also reduced. However, there was no significant difference, on average, in memory quotient or P300 latency between patients given rTMS plus donepezil hydrochloride and those given donepezil hydrochloride alone. Compared with the control groups, the rTMS treatment groups displayed slightly more frequent adverse reactions, mainly mild dizziness and scalp pain which disappeared within 1-2 hours without obvious residual effects.Conclusions:TMS treatment can effectively improve cognitive and memory function.