Abstract: Objective To the relationship between the degeneration of paraspinal muscles and postoperative clinical efficacy of short decompression and fusion in patients with degenerative lumbar scoliosis. Methods From December 2013 to December 2017，53 patients were treated for DLS with short decompression and intervertebral fusion.According to the preoperative MRI measurement of the paraspinal muscles cross section area（CSA）and the fatty rate，All patients was divided into the observation group（28 cases）and the control group（25 cases）.Preoperative measurement of Cob Angle，CSA and fatty rate of paraspinal muscles，visual analog scale（VSA），Oswestry dysfunction index（ODI）. Results There was no significant difference in Cob's angle，VAS and ODI between the two groups（P>0.05）.There was a significant difference in Cobb's angle between the two groups at 6 months after operation and before operation.12 months after operation，the Cobb's angle in the observation group was higher than that in the control group（P<0.05），while the VAS and ODI scores in the control group were better than those in the observation group（P<0.05）.There was significantly difference between the two groups in the CSA of the multifidus and the erector spinalis（P<0.05）.In the observation group，there was significantly difference in CSA between the concave side and the convex side（P<0.05）.There was significant correlation between the fatty rate and the postoperative ODI score，r=0.462. Conclusion Before operation，we should pay attention to the evaluation of the degree of degenerative paravertebral muscles，especially the fatty rate of the polysplit muscles，lengthen the fixed segment or strengthen the exercise of the lumbodorsal muscles，which is helpful to relieve the postoperative lumbodorsal pain.

Key words: degenerative lumbar scoliosis, paraspinal muscles, internal fixation