The patients with non-specific chronic low back pain (NCLBP) found a decrease in postural stability. However, only a few studies have been performed on the effects of sling exercise in NCLBP, and none of the studies examined postural stability after sling exercise. Therefore, the purpose of this study was to assess the anteroposterior (AP) and mediolateral (ML) postural stabilities of patients with NCLBP assessed on the sling and floor after exercise. Twenty patients with NCLBP aged 20 to 50 years were divided into sling exercise (n=10) and floor exercise (n=10). Both groups were trained 15 times/set for 3 sets, with 1-minute rest between a set. Postural stability was measured using an accelerometer in a seated position immediately after a training session. Before training, an appropriate training position for the patient’s abilities was suitable for all participants. Repeated measure ANOVA was used to analyze the difference in outcome measures within each group and between groups. The results showed a significant decrease of sway area AP direction and sway velocity in all directions in sling exercise (p<0.05); however, that was not for the floor exercise. Besides, the reduction in sway area in ML direction and sway velocity in all directions of the sling exercise was found significantly higher than the floor exercise (p<0.05). The sling exercise can reduce sway area and sway velocity in AP and ML. However, exercise on the floor was reduced the sway area only ML direction. But found that the sway velocity did not change. These findings suggest that the sling exercise is more effective in increasing postural stability than the floor exercise in patients with NCLBP.The patients with non-specific chronic low back pain (NCLBP) found a decrease in postural stability. However, only a few studies have been performed on the effects of sling exercise in NCLBP, and none of the studies examined postural stability after sling exercise. Therefore, the purpose of this study was to assess the anteroposterior (AP) and mediolateral (ML) postural stabilities of patients with NCLBP assessed on the sling and floor after exercise. Twenty patients with NCLBP aged 20 to 50 years were divided into sling exercise (n=10) and floor exercise (n=10). Both groups were trained 15 times/set for 3 sets, with 1-minute rest between a set. Postural stability was measured using an accelerometer in a seated position immediately after a training session. Before training, an appropriate training position for the patient’s abilities was suitable for all participants. Repeated measure ANOVA was used to analyze the difference in outcome measures within each group and between groups. The results showed a significant decrease of sway area AP direction and sway velocity in all directions in sling exercise (p<0.05); however, that was not for the floor exercise. Besides, the reduction in sway area in ML direction and sway velocity in all directions of the sling exercise was found significantly higher than the floor exercise (p<0.05). The sling exercise can reduce sway area and sway velocity in AP and ML. However, exercise on the floor was reduced the sway area only ML direction. But found that the sway velocity did not change. These findings suggest that the sling exercise is more effective in increasing postural stability than the floor exercise in patients with NCLBP.