To provide the clinical evidence by comparing the efficacy of Paraspinal Approach TLIF and Midline Approach TLIF for the treatment of single segment degenerative lumbar spinal stenosis.Method：From January 1, 2016 to February 1, 2018, 60 patients with single segment degenerative lumbar spinal stenosis who were operated in our hospital were analyzed retrospectively. The patients were treated with TLIF via posterior interhemispheric approach ((group A，30 cases) and TLIF via posterior median approach (traditional group，30 cases) . The operation time, Intraoperative bleeding volume, ambulation time，visual analog scale(VAS), Japanese Orthopedic Association(JOA) score and the multifidus muscle cross-section area in MRI were evaluated. Results：Comparing the operation time, intraoperative bleeding volume and ambulation time, group A was less than traditional group（P＜0.05）.The follow-up period ranged from 13-36 months, with an average of (26.22±8.97) months. There was no difference in VAS and JOA scores between the two groups before surgery (P> 0.05).The VAS score of the two groups decreased significantly with time, and the VAS score of the Wiltse group was significantly lower than that of the traditional group (P < 0.05). At 1, 6 months and last investigation after operation, JOA scores of the two groups were significantly increased compared with that before operation. Wiltse approach group was significantly higher than that of the traditional group (P < 0.05). The surgical segment and the multifidus of adjacent segments of the two groups of patients had a certain degree of atrophy. But the group A multifidus muscle atrophy rate is significantly lower than the traditional group. Conclusion：Compared with the traditional posterior Midline Approach, the use of the Paraspinal Approach (Wiltse approach) to treat single degenerative lumbar spinal stenosis can reduce the operation time, damage to the paravertebral musclesand the back pain. What's more, the Paraspinal Approach also has the advantages of less bleeding, less trauma, and faster recovery, which deserves further promotion in the clinic.