Objective To observe the therapeutic effects of UPASS-Ⅱ minimally invasive spinal system percutaneous pedicle screws internal fixation treating thoracolumbar fracture .Methods From May 2011 to December 2012 ,26 patients(observing group) were sufferred from thoracolumbar fracture without neural impairment were treated with UPASS-Ⅱ minimally invasive spinal sys-tem percutaneous pedicle screws internal fixation ,and were compared with other 26 cases(control group) adopted the treatment of conventional open pedicle screws internal fixation in the same period .Results All patients were followed up more than 6 months (mean 9 .2 months) ,the comparison of Cobb′s angle ,anterior vertebra height ,VAS ,JOA score and ODI between pre and post oper-ation were all significantly different in both group(P<0 .01) ,but the operation time and length of stay in the hospital in observing group were significantly shorter than that in control group (P<0 .05) ,moreover ,the amount of operative bleeding and drainage of post operation in observing group decreased obviously than that in control group (P<0 .01) .Conclusion This study shows that UPASS-Ⅱ minimally invasive spinal system percutaneous pedicle screw internal fixation treating thoraco-lumbar fracture is a safe and effective treatment strategy in selected patients .