Objective: To compare the efficacy of istradefylline (20mg/day, 40mg/day) and repetitive transcranial magnetic stimulation (rTMS) (1Hz, 10Hz) as an adjunct therapy to levodopa in the treatment of Parkinson's disease (PD). Methods: A total of 132 PD patients from China were randomly assigned to receive 20mg/day istradefylline plus sham-rTMS (Group I), 40mg/day istradefylline plus sham-rTMS (Group II), placebo plus 1Hz rTMS (Group III) and placebo plus 10Hz rTMS (Group IV) for 12 weeks. Unified Parkinson's Disease Rating Scale (UPDRS) part III score was the primary outcome. Clinical Global Impression-Global Improvement (CGI-I) was the secondary outcome. The change in daily off time in Groups I and II was also recorded. Results: After 12 weeks of treatment, the changes in UPDRS part III score were -6.05, -6.39, -5.91 and -6.46 for Groups I, II, III and IV, respectively, and the difference was not significant. The difference in CGI-I among the four groups was not significant. The daily off time was reduced by -1.43 hours in Group I and -1.62 hours in Group II. No severe adverse events occurred among the four groups. Conclusion: These results indicate that, as augmentation agents to levodopa in the treatment of PD, istradefylline and rTMS had comparable efficacy and tolerability.