Abstract:[Objective] To explore the safety and clinical efficacy of unilateral biportal endoscopy (UBE) in the treatment of multileveldegenerative lumbar disease ( MDLD). [Methods] Twenty nine patients who received surgical decompression with UBE for MDLD from July2020 to June 2022 were retrospectively analyzed. The clinical and imaging data were evaluated. [Results] All the 29 patients successfullycompleted the operation, with the average operation time of (178.6±26.5) min, the average intraoperative fluoroscopy times of (10.9±2.9). Interm of complication, dural tear happened in 2 cases, transient lower limb numbness in 2 cases, and epidural hematoma in 1 case, which notled serious consequence in anyone of them. The follow-up period lasted for (19.3±6.3) months in average. As time went from the point beforesurgery, to 7 days, 3 months and 12 months postoperatively, the VAS score for pain [(6.6±1.5), (3.2±0.5), (2.1±0.6), (1.7±0.5), P<0.001], ODIscore [(58.6±11.2), (33.5±4.6), (22.8±3.8), (17.5±2.2), P<0.001], JOA score [(15.6±2.4), (19.6±2.0), (21.2±2.2), (24.7±2.5), P<0.001] signifi-cantly improved. At 12 months after operation, the excellent and good rate was of 86.2%, according to the modified MacNab criteria. In termsof imaging, there was a significant increase in spinal canal area at 12 months after surgery compared with that preoperatively [(58.3±9.6)mm2, (118.4±14.2) mm2, P<0.001]. The retention rate of facet joints was more than 60% in all levels. [Conclusion] The UBE used in thetreatment of MDLD does achieve satisfactory clinical outcomes, with a benefit to maintain the stability of lumbar spine by preserving morefacet joints, is a safe and effective operation.