Abstract:[Objective] To compare the clinical outcomes and complications of transforaminal lumbar interbody fusion (TLIF) versus oblique lateral interbody fusion (OLIF) combined with pedicle screw fixation through posterior intermuscular channel approaches for degenerative diseases of the lumbar spine. [Methods] A retrospective study was conducted on 157 patients who underwent lumbar interbody fusion for lumbar degenerative diseases in our hospitals from January 2016 to December 2018. According to the doctor-patient communication, 81 patients received TLIF, while other 76 patients were treated with OLIF. The clinical documents, including complications, of the two groups were observed and compared. [Results] Although there were no significant differences in operation time and ambulation time between the two groups (P>0.05), the OLIF groups proved significantly superior to the TLIF group in terms of intraoperative blood loss [(79.8±26.5) ml vs (258.2±49.9) ml, P<0.05] and the hospital stay [(7.4±0.8) days vs (9.3±1.0) days, P<0.05]. With time of follow-up lasted for (20.8± 10.8) months on an average, the VAS scores for lower back pain and leg pain, as well as ODI score were significantly reduced in both groups (P<0.05), which was not statistically significant between the two groups at any time points accordingly (P>0.05). Radiologically, intervertebral height, coronal and sagittal Cobb angle of lumbar spine significantly improved in both groups at the last follow-up compared with those preoperatively (P<0.05), whereas which were statistically insignificant between the two groups at any time accordingly (P>0.05). Regarding to complications, the OLIF group was significantly higher in term of early incidence than the TLIF group (34.2% vs 19.8%, P<0.05), despite insignificant difference in late complication incidence between the two groups (1.3% vs 1.2%, P>0.05). [Conclusion] The incidence and composition of complications are different between the two lumbar fusion due to differences in spinal canal decompression methods, interbody fusion approach, size and area of fusion cage used.