Abstract:[Objective] To compare the clinical outcomes of unilateral biportal endoscopy lumbar interbody fusion (UBE-LIF), versusminimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF) for degree II~III lumbar spondylolisthesis. [Methods] FromJanuary 2019 to June 2022, a total of 249 patients who received surgical treatment for degree II~III spondylolisthesis were included in thisstudy, and were divided into two groups according to random number table method. Of them, 132 patients received UBE-LIF (the UBEgroup), while other 117 received MIS-TLIF (the MIS group). The perioperative, follow-up and imaging data of the two groups were com-pared. [Results] The operation was successfully completed in both groups without serious complications. The UBE group proved significant-ly superior to the MIS group in terms of intraoperative blood loss [(112.2±20.5) ml vs (132.9±25.8) ml, P<0.001], intraoperative fluoroscopytimes [(3.9±1.3) time vs (4.6±1.5) times, P<0.001] and walking time after operation [(1.6±0.5) days vs (1.9±0.3) days, P<0.001]. The averagefollow-up time was of (15.0±3.0) months, and the UBE cohort resumed full weight-bearing activity significantly earlier than the MIS [(65.5±10.2) days vs (68.9±11.6) days, P=0.015]. The VAS, ODI and JOA scores in both groups were significantly improved with the time after sur-gery (P<0.05). The UBE group was significantly better than the MIS group in terms of VAS [(2.4±0.4) vs (2.7±0.6), P<0.001], ODI [(29.2±6.7) vs (33.8±5.8), P<0.001], JOA score [(20.3±3.7) vs (18.6±4.2), P<0.001] 3 months after surgery. Radiographically, the extent of slippage,intervertebral height, lumbar lordosis, and local Cobb angle significantly improved in both groups at the last follow-up compared with thosepreoperatively (P<0.05), whereas which was not statistically significant between the two groups at any time points accordingly (P>0.05).[Conclusion] UBE-LIF achieves clinical consequence similar to MIS-TLIF for degree II~III lumbar spondylolisthesis. However, the UBELIFhas obvious advantages in reducing surgical trauma and improving short-term lumbar function over the MIS-TLIF.