Purpose : The purpose of this study is to evaluate morphology of acromion in relation to age and symmetry in asymptomatic adults. Materials and Methods: Seventy five asymptomatic adults were divided into two groups by age(A group of age twenties and B group of age over forty) and both acromial outlet views were obtained. One hundred fifty radiographs were typed and assessed radiologically by methods of Getz and Liotard. Results: The relative percentages of acromial types I, Ⅱ, and Ⅲ were 3%, 90% and 7% in the A group and 6%, 82% and 12% in the B group respectively, Subacromial peak and spinoacromial angle were 4.3mm, 82 degrees in the A group and 4.6mm, 78 degrees in the B group. Conclusion: Incidence of type is not related to age in normal adult and type II is the most common type. Spinoacromial angle is decreased in older age group and type Ⅲ