PURPOSE: The purpose of this study was to investigate the effect of short-term lumbar stabilization exercise to patients suffering from chronic low back pain(CLBP) on the strength of their lumbar flexor and extensor and the postural balance of them and to suggest effective treatment duration for them. METHODS: Study subjects were 20 patients with CLBP who`s been reported the pain for more than 12 weeks. For these subjects, muscle strength of both extensor and flexor of lumbar and the balancing ability were measured before and after the intervention. Lumbar stabilization exercise was composed of matt, ball and sling exercise. The intervention was applied for total 12 sessions for 4 weeks (3 times a week) and each session was for 40 minutes. RESULT: For muscle strength of both extensor and flexor of lumbar, there was significant differences after the application of lumbar stabilization exercise(p