Purpose : Purpose of this study was to investigate whether cervicothoracic posture was associated with scapula orientation and muscle activity during shoulder abduction. Methods : Cervicothoracic junction angle and thoracic kyphosis angle were measured in health twenty subjects. Then, scapular resting orientation and range of motion (upward/downward rotation, internal/external rotation) and muscle activity (upper trapezius, lower trapezius, serratus anterior) was determined using motion capture system and surface electromyography while subjects performed shoulder abduction. Results : Cervicothoracic junction angle was significantly associated with range of motion of scapular internal/external rotation during shoulder abduction. Thoracic kyphosis angle was significantly associated with scapular resting orientation of upward/downward rotation and average IEMG of lower trapezius. Conclusion : The result of this study shows that poor cervicothoracic posture is relationship with altered scapular kinematics cause of shoulder dysfunction. These findings suggested that cervicothoracic posture may be considered in occupation and exercise including arm elevation over head as well as used as predict factor to estimate shoulder dysfunction.