Purpose : Recently ultrasound images has been used to measure the subacromial space with a linear measurement of the acromiohumeral distance. The purpose of this study was to comparison of distance of subacromial space using ultrasonographic measurement on arm positions of shoulder injured patients. Methods : The subjects were 30 shoulder injured patients (19 males and 11 females). Ultrasonography was performed to measure subacromial space during each shoulder resting position, $45^{circ}$ abduction, internal rotation with $45^{circ}$ abduction and external rotation with $45^{circ}$ abduction. Results : Subacromial space was a significantly difference between injured arm and normal arm at shoulder resting position. At $45^{circ}$ abduction, subacromial space was narrowing significantly between injured arm and normal arm. At external rotation with $45^{circ}$ abduction, subacromial space were wider in normal arm than in injured arm but it was not significantly. Intra-observer reliability for ultrasonography measurement of subacromial distance was excellent (.96~.99). Conclusion : These results identified that positions of injured shoulder was related to subacromion space.