Objective To study the efficacy of repetitive transcranial magneticstimulation(rTMS) of the right prefrontal cortex combined paroxetine for patients with obsessive-compulsive disorder ( OCD) under doubleblind , sham-controlled conditions. Methods Patients were randomly assigned to 2 sessions of real ( n = 32) or sham ( n = 31) rTMS and both group received Paroxetine treatment. rTMS treatments lasted 20 minutes,and the frequency was 10 Hz and the intensity was 100% of motor threshold for real rTMS. Psychopathology was assessed by HAMA.Y-BOCS before the treatment,immediately after the experimental treatment,and 1,2,4,6 weeks after the experimental treatment by an independent reviewer. Results In combined therapy group,9(32. 14% ) recovered, 10(35.71% ) remitted,5( 17. 86% ) improved,4( 14. 29% ) remained unresponsive. In contrast,there were 4(16.36%) recovery,5(21.82%) remission, 10(38.18% ) improvement,6(23.64% ) unresponse in drug therapy group. The outcome of ITT showed all the patients in the two groups significant improvement (the scores of YBOCS( F=56.258, P=0.000) ;the scores of HAMA( F=41.675, P=0.000) after the treatment,but the effectiveness in the combined therapy group was better than that in the drug therapy group (the scores of Y-BOCS, F= 13.652, P=0.028;the scores of HAMA, F= 11.632, P=0.031). Conclusions Repetitive transcranial rTMS of the right prefrontal cortex combined paroxetine is more effective than paroxetine only in treatment of refractory OCD.