Objective To explore the effects of repetitive transcranial magnetic stimulation (rTMS) on the improvement of cognitive function and serum C-reactive protein (CRP) of inpatients with chronicschizophrenia, in order to probe the possible mechanism of rTMS on the cognitive function. Methods To-tals of 60 participants were selected from the inpatients of Tianjin Mental Health Center from January, 2013 to January, 2016. They were paired by the severity of the disease, gender and age. Either patient was treated byreal rTMS or sham rTMS for 4 weeks by random in each pair. Positive and Negative Symptom Scale (PANSS) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were assessed twice (before andafter treatment) in all participants. Serum CRP was determined simultaneously. Results (1) Level of CRP was declined significantly in treatment group (P ＜0.05), but not in control group; (2) Compared to the baseline, the total score and Negative factor score of PANSS in treatment group were statistically decreased (P ＜0.05), while there was no change in control group; (3) The total score and the scores of visual span, attention and prolonged memory in RBANS were significantly improved in treatment group (P ＜0.05), no changes were found in control group; (4)In treatment group, there was the negative correlation between “Δtotal score of PANSS”and“Δimme-diate memory”,“Δnegative factor score of PANSS”and“Δtotal score of RBANS”,“Δnegative factor score of PANSS”and“Δprolonged memory”respectively(P ＜0.05); (5)There was negative correlation between “Δtotal score of RBANS”,“Δscore of immediate memory”,“Δscore of attention”and“Δscore of prolonged memo-ry”and“ΔCRP”(P ＜0.05) separately. Conclusions rTMS could improve cognitive function of patients with chronic schizophrenia, and the possible mechanism may be the remission of inflammatory reaction.