BACKGROUND：Stress urinary incontinence （SUI） is a common health problem aff ecting women with a wide range of age. Although the pelvic fl oor muscles （PFM） exercise is the highly recommended fi rst-line treatment for SUI, its adherence is low. Recently, urinary incontinence is reported to have an association with high pelvic fl oor stiff ness. A PFM massage, more feasible than the PFM exercise, may have a positive eff ect on urinary incontinence symptoms. However, there are no previous studies published. OBJECTIVE：This study examined the eff ects of self-massage （SM） to PFM on symptom of SUI among younger and middle-aged women. METHODS：Multiple baseline design （N-of1 trial） was utilized. After 2 or more-weeks control period, all participants （N=34） were asked to conduct SM to PFM once a day, 5 days a week, for 6-9 weeks. All instructions and survey were conducted via web and e-mails. As a primary outcome, self-reported symptoms of urinary incontinence were examined with International Consultation on Incontinence Questionnaire-Short Form （ICIQ-SF） at the beginning of research, and baseline, every two weeks during and after intervention. For single case design, Percentage of Non-overlapping Data （PND） was calculated. Friedman's test was performed for the pre-post single arm design. RESULTS：About 35% of participants visually improved ICIQ-SF score after intervention period （PND ≥ 70%） whereas 65% showed no or deleterious change （PND < 70%）. Median ICIQ-SF scores were signifi cantly increased after control period and signifi cantly decreased over time during intervention period. CONCLUSION：The present fi ndings suggest the SM to PFM may be conducted safely and feasibly, and have some possibilities to improve symptom of SUI.