[Abstract] Objective To investigate the effect of perimenopausal depression on the expression of key genes of Notch signaling pathway and DNA methylation of its promoter in rat hippocampus from the perspective of DNA methylation of epigenetics. Methods 12-month-old female SD rats were randomly divided into control group and model group. Open field tests, sugar consumption tests, and forced swimming tests were used for behavioral evaluation. Real-time PCR was used to detect the expression of key genes of Notch signaling pathway in the hippocampal dentate gyrus of different groups. Bisulfite sequencing (BSP) was used to analyze methylation sites and methylation levels in the promoter region of key genes of the Notch signaling pathway. Results In perimenopausal depression rats, the horizontal and vertical scores of open field test and the rate of sugar water consumption decreased significantly; the expression of the key genes Jagged1, Notch1 and Hes5 on Notch signaling pathway was significantly down regulated in the hippocampus of perimenopausal depression rats (P＜0.01 or P＜0.05) ; among them, some methylation sites and methylation rates of Hes5 gene increased significantly, while the methylation sites and methylation rates of Jagged1 and Notch1 genes were not statistically significant (P>0.05) . Conclusion The expression of key genes of Notch1 signaling pathway in the hippocampal dentate gyrus of perimenopausal depression rats is significantly down regulated, and the down-regulation of Hes5 gene may be related to the increase of promoter DNA methylation level.