Recurrent glenohumeral instability can be classified into two large groups the acronym TUBS and AMBRI groups. Rockwood, Depalma, and others described that the distinction to TUBS or AMBRI group was the most important factor for the selection of the treatment methods in recurrent shoulder dislocation. The commonest lesion in TUBS group is avulsion or rupture of the anterior glenohumeral ligament from the glenoid, which often called Bankart lesion. Recently, various arthroscopic surgical methods including stapling, suture and biodegradable stock were reported for the treatment of recurrent shoulder dislocation. Twenty-one patients who had recurrent anterior instability of the shoulder were treated with arthroscopic repair of the Bankart lesion by suture technique at the Chung-Nam National University Hospital from January-1989 to June-1991. We assessed arthroscopic findings and results of follow up. All affected shoulder were found various degrees and shapes of the Bankart lesion at the intraoperative arthroscopic examination, and we could identify and classify the Bankart lesion into four different types that were as follows, 1. Type I: Separation of labrum and inferior glenohumeral ligament from the glenoid rim and scapular neck (6 cases). 2. Type II: Separation of labrum with glenoid rim fracture (5 cases). 3. Type III: Above type I or type II lesion with SLAP lesion (4 cases). 4. Type IV: Deficient labrum with detached loose inferior glenohumeral ligament from.