[Abstract] Objective To study the clinical efficacy of unilateral biportal endoscopic decompression of the responsible spinal canal in the treatment of degenerative lumbar spinal stenosis (LDSS) in the elderly. Methods 65 cases with LDSS admitted to our hospital from January 2018 to March 2021 were selected.Unilateral biportal endoscopic decompression group (UBE group) 28 cases and traditional operation group 37 cases. The perioperative data of the two groups were compared (including operation time, intraoperative bleeding, hospital stay, incision length, bed rest time, etc.), visual simulation score（VAS）, Oswestry dysfunction index(ODI), vertebral canal cross-sectional area(CSA) and the diameter of the lateral recess before and after operation. Results ① The operation time of UBE group was significantly higher than that of the traditional group (P<0.001), and the intraoperative bleeding, hospital stay, incision length, bedtime and complications were significantly lower than those of the traditional group (P<0.05). ② All patients were followed up for 12-16 months, with an average of 14.12 ± 1.05 months. There was no osteoporotic vertebral fracture or reoperation during the follow-up period. 1 month after operation, the VAS score and ODI score of UBE group were significantly better than those of traditional group (P<0.05). 3 months after operation and at the last follow-up, there was no significant difference in VAS score and ODI score between the two groups (P>0.05), which were significantly better than those before operation (P<0.001). ③ The average time of interbody fusion in the traditional group was 3.41 ± 1.08 months. There was no significant difference in the diameter of the lateral recess and CSA before operation (P>0.05). The diameter of the lateral recess and the CSA in the two groups were significantly increased after operation than before operation, and the difference was statistically significant (P<0.001). There was no significant difference between the two groups (P>0.05). Conclusion Unilateral biportal endoscopic decompression of the responsible spinal canal has significant short-term clinical effect on senile degenerative lumbar spinal stenosis, which could effectively relieve pain and improve the quality of life .