Shoulder arthroscopy is a diagnostic method, so there is no absolute indication that arthroscopy must be used. However, the use of arthroscopy for some shoulder conditions can provide further clarification of the diagnosis and a clearer understanding of the pathological changes of the disease, and sometimes surgical management is possible. Arthroscopic surgery can be considered in the following cases. 1.Joint free body: clear diagnosis and removal of the free body. 2.Painful joint instability (habitual dislocation or subluxation): clarify the site of joint capsule and glenoid lip injury, and feasible repair surgery. 3.Biceps rupture: understand the extent of the rupture, remove the severed end, and reduce pain. 4.Rotator cuff rupture: For acute complete rotator cuff injury, arthroscopy is not recommended because the joint capsule cannot be inflated due to fluid leakage. For chronic rotator cuff rupture, the lesion can be clarified, and for incomplete injury, the severed end can be trimmed to reduce pain. 5.Osteoarthritis: debridement and irrigation. 6.Septic arthritis of shoulder: clean up and rinse. 7.Shoulder impingement syndrome: perform subacromial arthroscopy and also perform acromioplasty.