Abstract: [Objective] To investigate the effects of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of L4/5 single-segment lumbar spinal stenosis and adjacent segment degeneration (LSS) and influence on adjacent segment degeneration (ASD). [Methods] patients with L4/5 single-segment LSS admitted in our hospital from January 2016 to January 2018 were collected and divided into conventional transforaminal intervertebral fusion groups (TLIF group, n=76) and MIS-TLIF group (n=52). The surgery-related indicators were compared between groups. The efficacy was evaluated by pain visual analogue scale (VAS),Oswestry dysfunction index (ODI) and improved MacNab standard. The lumbar lordosis (LL), fused segment angle (FSA) of L4/5 and the range of motion (ROM), disc height (DH) of adjacent segment were measured by imaging, the superior facet joint violation (FJV) was measured. [Results] The operation time in the MIS-TLIF group was longer than that in the TLIF group, but the length of the incision, the intraoperative blood loss, the drainage volume at 24 hours after the operation, and the length of hospital stay were lower than those in the TLIF group (P<0.05). The VAS and ODI scores of the two groups were lower than those before surgery, but there was no significant difference between the groups (P>0.05). According to the modified MacNab standard, the excelllent and good rate of the MIS-TLIF group and TLIF group was 88.46% and81.58%, the difference was not statistically significant (P>0.05). At 12 months after surgery, there was ROM increased and DH loss of adjacent segment in both groups (P<0.05), but the DH loss and ROM increase in L3,4 segments in the MIS-TLIF group were lower than TLIF group (P<0.05). The incidences of FJV and ASD in the MIS-TLIF group were 13.46% and 9.62%, which were lower than the 36.84% and 28.95% in the TLIF group (P<0.05). [Conclusion] MIS-TLIF is safe and effective in the treatment of L4/5 single-segment LSS, which can achieve the near-to-medium-term efficacy equivalent to conventional TLIF, and can reduce the risk of ASD.