Abstract: Objective To investigate the intervention effects of repetitive transcranial magnetic stimulation (rTMS) on preclinical Alzheimer disease (AD) patients and the characteristics of brain functional changes during the intervention. Methods A total of 29 patients with subjective cognitive decline (SCD) or amnestic mild cognitive impairment (aMCI) were recruited from Nanjing Brain Hospital. Each subject received approximately two weeks of rTMS intervention. A comprehensive neuropsychological assessment battery was used to evaluate the cognitive function changes in both groups before and after the intervention. Resting-state functional magnetic resonance imaging (rs-fMRI) indices, including fractional amplitude of low-frequency fluctuations (fALFF) and regional homogeneity (ReHo), were analyzed to assess the therapeutic effects. Results After treatment, the SCD group showed significant improvements in the Auditory Verbal Learning Test 20-minute delayed recall (AVLT-20min-DR), AVLT-total score(AVLT-total), Logical Memory Test immediate recall (LM-at once), and Logical Memory Test 20-minute delayed recall (LM-delay) (P<0.05). Brain regions with significantly increased fALFF values included the right inferior parietal lobule and the right middle occipital gyrus, while significantly decreased fALFF values were observed in the right lingual gyrus and the right angular gyrus. In the aMCI group, significant improvements were found in AVLT-20min-DR, AVLT-total, Rey Complex Figure Test 20-minute delayed recall (Rey-20min), Category Verbal Fluency Test-market (COWAT-market), and Digit Span Test (DST) (P<0.05). After treatment, fALFF values significantly increased in the right precuneus and decreased in the right middle cingulate cortex. Additionally, the ReHo value showed significant differences in the left middle occipital gyrus after treatment. Conclusions rTMS has a positive effect on improving memory, attention, and executive functions in preclinical AD patients.