Objective: The purpose of this study is to compare chronic low back pain patients pain provocation position so as to identify the relevance with lumbar stabilizing muscles atrophy and pain provocation position. Design: Cross-sectional study. Methods: Fifty five chronic low back pain patients were participated in this study. Subjects were eligible for study participation if they were 35-55 years old and had experienced low back pain for more than 3 months. Subjects were questioned about pain and pain provocation test were done. And then they were inspected their cross sectional area (CSA) of lumbar muscles (erector spinae, iliopsoas, and multifidus) by using computed tomography. Analyze the relevance through the result data with painful area, aspect of pain and pain provocation position. Results: CSA of erector spinae showed significant decrease on ipsilateral extension position (p＜0.05). Iliopsoas muscle showed significant decrease on contralateral position (p＜0.05). Multifidus showed significant decrease on the position of contralateral extension and contralateral flexion (p＜0.05). Conclusions: Based on the results of our study, it may be possible to evaluate muscle atrophy by assessing causing position.