Abstract:[Objective] To compare the clinical efficacy of two kinds of endoscopic decompression in the treatment of lumbar spinal ste- nosis. [Methods] A retrospective study was conducted on 213 patients who received endoscopic surgery for lumbar spinal stenosis in The Second Affiliated Hospital of Anhui Medical University and the Third People's Hospital of Hefei City from May 2018 to May 2021. Accord- ing to doctor-patient communication, 132 patients underwent unilateral biportal endoscopy (UBE), while the other 81 patients were treated with endoscopic foraminoplasty and decompression (EFD). The perioperative period, follow- up and imaging data of the two groups were compared. [Results] All the patients in both groups were operated on successfully. The UBE group proved significantly superior to the EFD group in terms of dural tear [1 (0.8%) vs 5 (6.2%), P<0.05] and nerve root injury [2 (1.5%) vs 6 (7.4%), P<0.05], as well as intraoperative ra- diation exposure time [(1.1±0.1) min vs (3.3±0.6) min, P<0.05], nevertheless, there were no significant differences in operation time, postop- erative infection rate, postoperative walking time and hospital stay between the two groups (P>0.05). All of them in both groups were fol- lowed up for more than 12 months, without a significant difference in the time to return to full weight-bearing activities between the two groups (P>0.05). The VAS scores for both low back pain and leg pain, and ODI score significantly decreased in both groups at the latest fol- low-up compared with those preoperatively (P<0.05), which proved not significantly different between the two groups at any corresponding time points (P>0.05). Radiographically, compared with those preoperatively the height of involved vertebral space, sagittal diameter of later- al recess, sagittal diameter of central spinal canal and lumbar lordosis angle (L1~S1 Cobb angle) were significantly increased in both groups 3 months after surgery and at the last follow-up (P<0.05). Although there was no significant difference in the abovesaid imaging indexes be- tween the two groups before surgery (P>0.05), the UBE group got significantly greater sagittal diameter of lateral recess [(12.0±3.7) mm vs (9.8±2.8) mm, P<0.001] and sagittal diameter of central spinal canal [(15.7±3.8) mm vs (9.8±2.1) mm, P<0.001] than the EFD group post- operatively. However, there were no statistically significant differences in the height of intervertebral space and lumbar lordosis angle be- tween the two groups at any time points accordingly (P>0.05). [Conclusion] The UBE does improve the symptoms of patients with lumbar spinal stenosis and achieve satisfactory clinical outcomes, especially for bilateral and severe lumbar spinal stenosis, which is superior to unilateral transforaminal endoscopies.