Objective To review the present clinical research situation of adjacent segment degeneration (ASD) after lumbar spinal fusion. Methods The recent literature concerning ASD in the concept, the incidence, the risk factors, and prevention was reviewed. Results The concept of ASD includes radiographic ASD and clinical ASD. The incidences of radiographic ASD and clinical ASD were 8%-100% and 5.2%-18.5%, respectively. The risk factors for ASD include both patient and surgical factors. Patient factors include age, gender, preoperative condition, and so on. Surgical factors include the length of the fusion, mode of fusion, internal fixator, sagittal balance, excessive distraction of disc space, and so on. It can prevent ASD to reduce the length of the fusion, to keep sagittal balance, and to use the non-fusion technology. Conclusion Many researches have proved that the incidence of ASD is increased after lumbar spinal fusion, and it can be reduced by the non-fusion technology. Non-fusion technology has obtained good short-term results. But the long-term results should be further observed because there are some complications.