This article is to evaluate the correlation between dermatomal somatosensory evoked potentials(DSEP) improvement and clinical outcome in patients with lumbosacral radiculopathy received nerve root decompression.Twenty two patients diagnosed as radiculomedullary were confirmed by the CT or MRI screen,they were investigated preoperatively and 9 week postoperatively.Compared with the preoperative,the postoperative clinical symptoms of the patients were significantly improved( P