This invention provides an ultrasonic guidance method of subacromial bursa, which images subacromial bursa easily under ultrasound through specific positioning with patient's another hand appropriately pushing the elbow joint and allow needle insertion through near-end needle insertion from long axis of supraspinatus tendon. Moreover, the bursal fluid can be positional drained by the specific positioning and ultrasonic detector is moved to a sagittal plane around a greater tubercle of humerus for drawing bursal fluid through near-end needle insertion. As a result, in the invention, it is to medially rotate greater tubercle of humerus as possible to prevent lower margin of scapular bone from blocking the imaging of subacromial bursa and to allow SASD bursal fluid pooling near greater tubercle of humerus.