Abstract: [Objective] To compare the clinical efficacy and degree on paraspinal muscles injury of unilateral biportal endoscopy (UBE) and open lumbar interlaminar fenestration decompression for the treatment of degenerative lumbar spinal stenosis (DLSS). [Methods] The data of 68 cases of DLSS admitted to our department from October 2019 to October 2020 were retrospectively analyzed. Based on doctor-patient communication results, 36 cases were treated with UBE (Endoscopic group) and 32 cases were treated with open lumbar interlaminar fenestration decompression (Open group). The perioperative, follow-up and imaging data were compared between the two groups. [Results] All patients completed the surgery successfully without serious surgical complications. The length of the surgical incision, the early ground and the hospital stay time were lower in Endoscopic group than in Open group (P<0.05). The creatine kinase (CK) value of Endoscopic group was lower than that of Open group at 1 day (P<0.05), and there was no difference at 7 days (P >0.05). Over time, the VAS, ODI and JOA scores in both groups were improve than before surgery and tend to be better (P<0.05). The VAS, ODI scores in Endoscopic group were lower than that of Open group at 7 days after surgery (P<0.05), while the JOA scores were higher than in open group (P<0.05). There were no differences in VAS, ODI and JOA scores at 3 months after operation and last follow-up (P>0.05). At the final follow-up, spinal canal area in Endoscopic group was smaller than that in open group (P<0.05).The cross-sectional area in Endoscopic group was larger than that in Open group (P<0.05), while paravertebral muscle atrophy rate was smaller than that in open group (P<0.05).[Conclusion] UBE has the advantages of less trauma and faster postoperative recovery in the treatment of DLSS, and effectively reduces and avoids damage to the paravertebral muscles during surgery, and can achieve the same clinical results as open surgery.