Objective To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on the depressive like behaviors and expression of brain derived neurotrophic factor (BDNF),IL-1β and NF-κB of hippocampal in chronic unpredictable mild stress (CUMS) rats.Methods Thirty-two adult male rats were randomly divided into four groups (n =8):Control group,Control + rTMS group,CUMS group and CUMS + rTMS group.The sucrose preference test,forced swim test and open field test were used to evaluate depressive like behaviors for each groups.In addition,the expression of BDNF,NF-κB and IL-1 β in hippocampal were detected by western blot and ELISA after behavioral test,respectively.Results 1.The effects of rTMS on depressive like behaviors of CUMS rats:in the sucrose preference test,the sucrose preference rate of CUMS rats (0.67 ± 0.06) was significantly lower than Control group (0.91 ± 0.04),which was higher in the CUMS + rTMS group (0.83 ±0.08).In the forced swim test,the immobility time of CUMS group ((26.88 ± 11.33) s) was longer than Control group ((15.22 ± 6.75) s) and CUMS + rTMS group ((18.41 ± 6.95) s).In the open field test,both the total distance travelled and number of central area entry times of CUMS group((849.165 ± 769.01) cm,(7.42 ± 5.68))were significantly shorter ((6224.81 ± 1403.2) cm) and smaller (22.86 ± 3.72) than Control group,and those of the CUMS + rTMS were longer ((4105.57 ± 1516.92)cm) and larger (21.25 ± 3.45).All the behavioral results were statistically significant (P＜ 0.05).And of all the aforementioned behavioral parameters,there were no significant differences between Control group and Control + rTMS group(P＞0.05).2.The effects of rTMS on the hippocampal expressions of BDNF,NF-κB and IL-1β in CUMS rats:compared with Control group,the hippocampal expression of BDNF in CUMS rats was significantly decreased,while the expressions of NF-κB and IL-1β in the hippocampus were significantly increased (P＜ 0.05).Compared with CUMS group,the hippocampa expression of BD-NF in the CUMS + rTMS group was increased,and the expressions of NF-κB and IL-1β in the hippocampus was significantly decreased (P ＜ 0.05).The expressions of BDNF,NF-κB and IL-1β had no differences between Control group and Control + rTMS group.Conclusion rTMS increased the expression of BDNF,reduced the production of NF-κB and IL-1β,and alleviated depressive like behaviors in CUMS rats.