The purpose of this study identify that spinal decompression therapy effect on and pain, length Of leg distance(LLD), and muscle power and flexibility in patient with low back pain. The participants is 20 female and male with low back pain, and participant assign to decompression therapy group and control group at random. The decompression therapy apply to 20 minute 3 time for a week during 4 weeks. The Measurement items is pain, LLD, and muscle power, flexibility. The comparison between the before and after was Wilcoxon's U test, and 2 group after spinal decompression therapy application compared Mann-Whithney U test. Spinal decompression therapy reduced statistically significance the pain, LLD, and increased statistically significance the muscle power and flexibility increased the muscle power(p<.05). This study showed that spinal decompression therapy does affect pain, LLD, and muscle power and flexibility in patient with low back pain.