Purpose : The purpose of this study is to investigate the instant effect of Kinesio taping on pain decrease and improvement of functional disorder of the subjects who have lumbar instability. Methods : A total of 20 patients (13 men and 7 women) who have lumbar instability were chosen as the subjects. The experiment was conducted by assigning the subjects into Kinesio taping group and placebo taping group. A visual analog scale (VAS) was used to measure back pain and Biering-Sorensen test was applied to measure the muscle endurance of back extensor muscles. A digital dynamometer was used to test the isomeric contraction strength of lumbar extensor muscle. The subject performed single-leg stance and double-leg stance task and their static balancing ability was measured by a testing device that captures the static balancing ability. Results : In a within-group comparison, Kinesio taping group showed a significant decrease of VAS (p＜.05) and a significant increase of endurance and strength of lumbar extensor muscle (p＜.05). In Kinesio taping group, the shift distance in anterior-posterior sway and medial-lateral sway during the double-leg stance significantly decrease (p＜.05). The shift distance in anterior-posterior sway and medial-lateral sway also significantly decreased during the single-leg stance (p＜.05). Placebo taping group showed a significant decrease of visual analog scale (p＜.05). In a between-group comparison, Kinesio taping group showed a significantly larger decrease of VAS (p＜.05), significant larger increase of muscle endurance and muscle strength (p＜.05), and significant larger decrease of anterior-posterior sway in the double-leg stance (p＜.05), compared to placebo taping group. Conclusion : Application of Kinesio taping to the subjects with lumbar instability produced positive effect of reducing pain, increasing muscle strength and endurance, and improving static balancing ability.