The clinical effects of a Xenon Flash Low Frequency Therapy apparatus(Xenon 550) and Nerve block were evaluated in 52 outpatients with low back and legs pain in the pain clinic of the First Teaching Hospitol of in Norman Bethune University of Medical Sciences. 52 patients (male 30, fernal 22), were indivied into 3 groups: group 1 treated with ultrashort waves; group 2 receiving Xenon Flash Low Frequecy Therapy and groups 3 treated with Xenon Flash Low Frequecy therapy and nerve block in epidural space or intervertebral foramen. Clinical effects were evaluated by measuring changes in subjective symptoms and the comfort ability of each group before and after treatment by means of the Visual Analogue Scale(VAS) and comfort level. The results showed that symptoms were signifciantly improved in the group 3 compared with the group 1 and 2. Our findings suggest that this appratus and nerve block of epidural spare or intervertebral foramen provided a new method for treating low back and legs pain with high comfort levels.