Objective To compare the clinical results of small surgical incision of bilateral spinous process and traditional open surgical incision in posterior single level lumbar interbody fusion,and assess the application value of the small surgical incision of bilateral spinous process in posterior single level lumbar interbody fusion.Methods From December 2006 to June 2008,70 patients with lower lumbar vertebral diseases underwent single segment posterior lumbar interbody fusion.Patients were randomly divided into small surgical incision of bilateral spinous process group(Hereinafter referred to as small incision group) of 36 cases and 34 cases of conventional open group.Small incision group included 20 males and 16 females with an average age of 52.0 years.Traditional open group included 16 males and 18 females with an average age of 53.2 years.Two groups of operative time,blood loss,postoperative drainage,X-ray projection operation frequency,hospital stay,complication rate,creatine phosphokinase (CPK) level,multifidus cross-sectional area,postoperative low back pain visual analogue scale(VAS),Oswestry disability index(ODI),interbody fusion rate were compared,respectively.Results All of 70 cases were followed up for 12-24 months (average,16).There were no statistically differences in the operation time,the number of X-ray projection,complication rate,and fusion rate between the two groups (P>0.05),but there were significant differences in blood loss,postoperative drainage,the first day and the third day of postoperative the level of CPK,postoperative multifidus muscle cross-sectional area,postoperative low back pain VAS,hospital stay,and postoperative ODI between the two groups (P<0.05).Conclusion Small surgical incision of bilateral spinous process and traditional open surgical posterior lumbar interbody fusion were satisfied with the efficacy,but small surgical incision of bilateral spinous process with less trauma,shorter hospital stay,and rapid postoperative recovery. Key words: Lumbar vertebrae; Spinal fusion; Surgical procedures, minimally invasive