Lumbar interbody fusion is the primary treatment of degenerative lumbar diseases; however, the outcome of the operation is seriously affected by the postoperative adjacent segment pathology (ASP), and some patients even need revision surgery. Many factors affect the occurrence of ASP, including age, preoperative adjacent segment degeneration, sagittal imbalance, length of fusion segment and surgical methods. Meanwhile, great progresses, such as minimally invasive and non-fusion surgery, have been made in treating ASP. This paper reviews the pathogeny, risk factors and treatment of ASP.