Background: This study investigated the effects of pelvic floor stabilization exercise of pain, disfunction, psychosocial, electromyography (EMG) activity on the lower back pain with postpartum. Methods: The study included 20 postpartum women who were randomly assigned to a sling exercise group (SEG, n=10) or a general physical therapy group (GPTG, n=10). Outcomes were assessed using to lower back pain with postpartum the quadruple visual analogue scale (QVAS), the Korean version of the Oswestry disability index (KODI), the fear avoidance belief questionnaire (FABQ), the inventory of functional status after childbirth (IFSAC), the edinburgh postnatal depression scale-Korean (EPDS-K), and trunk muscle activity before and after a 4-week exercise intervention. Statistical analysis were performed using a mean, standard deviation, crosstab test, paired t-test, independent t-test. Kolmogorove-Smirnov test was used for test of normality. Results: Compared to the GPTG, the SEG showed significant improvement in the QVAS, KODI, FABQ, IFSAC, and EPDK-K scores (p<.05) after 4 weeks. Conclusion: Postpartum pelvic strengthening exercise proved to have a positive effect.