Abstract:Objective: To explore the effect of freezing selective dorsal ramus of spinal nerve for low back pain. Methods: Depending on the location of low back pain, the real painful point and the dorsal ramus is identified. A freezing needle is inserted. If patient felt ache, swelling and heaviness and those feeling were conducted to buttock, thigh and knee but not to the leg, this position was accurate, and one can begin to freeze for three freeze cycles. The cryotherapy mas made according to the number of painful points. Results: 129 cases were treated. The total rate of excellent and good was 60%, effectiveness was 88%. A best result was obtained for the treatment of chronic injury of lumbar muscle and zygapophyseal joint disorder, with the rate of excellent and good of 58% and 84%, effectiveness rate 88% and 100% respectively. Conclusion: Cryotherapy on selective dorsal ramus of spinal nerve produces a relief of low back pain probably due to a partial block of pain conductance. Selection of patients before operation and the accurity of the operation are important factors derermining the efficacy of cryotherapy.