Objective To explore the ideal minimally invasive surgical method for degenerative lumbar spine stenosis.Methods From March 2008 to August 2010,73 cases with lumbar spinal stenosis underwent minimal invasive surgery were retrospectively analyzed.The patients were divided into different groups by clinical features,imaging manifestations,and concurrent diseases.The minimal invasive surgical methods were chosen according to the classification.Operation time,intra-operative bleeding,and complications were recorded.The lumbar function was evaluated by Oswestry disability index (ODI),and the clinical results were assessed by JOA pre- and postoperatively.Results Minimal invasive surgery was completed in all cases,which included 25 cases with bilateral decompression and 48 cases with unilateral approach for bilateral decompression.Twenty-three cases used interbody fusion and percutaneous pedicle screw fixation after decompression.Intraoperative blood loss and operation time were related to surgical methods.One case was complicated with dural tear.Cage was inserted into upper vertebral body during interbody fusion in 1case with osteoporosis,removed the cage and implanted bone fusion.Incisions of 3 cases were poor healing after surgery.The average follow up time was 13 months (range,10-35).JOA score and ODI before surgery were 9.2±5.1 and 62.3%±18.5% respectively; while 6 months after surgery,JOA score and ODI were 23.5±7.2 and 18.4%±6.4% respectively.JOA score and ODI showed statistically significant improvements after operation (P<0.01).Twenty-two cases got solid fusion at the final follow-up.Conclusion Treatment of lumbar spinal stenosis by minimal invasive surgery has satisfactory surgical outcomes,but the proper minimal invasive strategy should be chosen according to specific patients,surgeons and hospitals. Key words: Surgical procedures, minimally invasive; Lumbar vertebrae; Spinal stenosis