目的　通过CT征象分析 ,探讨退变性脊椎滑脱症的病因。方法　对 12 5例 131个滑椎的滑脱部位、程度及滑椎小关节面倾斜角进行测定。结果　 131个滑椎中小关节面倾斜角 <90°者占多数。 5 0岁以上者占三分之二。有一小部分DS者小关节倾斜角≥ 90° ,且无小关节病。结论　椎小关节倾斜角减少是DS的先天因素。在后天因素中 ,脊椎周围肌肉韧带薄弱、松驰起着相当重要的作用 Objective To investigate the etiology of degenerative spondylolisthesis by CT sign analysis. Methods The spondylolisthesis and degree of 125 lumbar spondylolisthesis and the inclination angle of the facets of the spondylolisthesis were measured. Results 131 of the vertebral facet joint surface tilt angle <90 ° accounted for the majority. Two-thirds of those over 50 years old. A small proportion of DS have a facet joint angle of inclination ≥ 90 ° and no facet joint disease. Conclusions Decreasing the inclination angle of facet joint is the congenital factor of DS. In acquired factors, the muscles around the spine ligament weak, loose play a very important role