Forty-five modified arthroscopic transglenoid suture capsulorrhaphy were performed between January 1989 and May 1995 with minimum follow-up of one year among sixty-four recurrent anterior shoulder instability in Chungnam National University Hostital. The average age at operation were 25 year and average time interval from injury to surgery were 12 month. we classify the Bankart lesion into 4 type according to the extent of capsulolabral complex detatchment, associated glenoid rim fracture, type II SLAP lesion and absence of glenoid labrum. Type Ia have a separation of labrum and inferior glenohumeral ligament from the glenoid rim and scapular neck (classic Bankart lesion) and type IIa have a capsular separation and glenoid rim fracture. Type IIIa have above mentioned type Ia or type IIa with type II SLAP lesion and type IVa have capsular separation without identifiable labral structure. We also subdivided the each type into subgroup b according to coexistence of capsular laxity. We modify the capsular suture technique according to classification. Type Ia, and type IIa were treated with in situ Bankart repair. Type Ib and type IIb were treated with capsular advancement. Type IIIa and 1IIb were treated with Bankart repair and additional fixation of SLAP lesion. Type IVa and IVb were treated with purse string type suture (capsular shift superiorly) with multiple stitches. All patients had various shape of Bankart lesion, so author s proposed classification of the Bankart lesion can be applied to each type. Arthroscopic finding were as follows. Twelve shoulders (27%) have type Ia Bankart lesion and six patient (13%) have type lIa lesion. Type lIIa were observed in eight shoulders (18%) and four patient (9%) were type IVa. The capsular laxity (subgroup b) were found in 15 patient (33%). None of the 45 patients experienced intraoperative complications or infec tion. All patients had full, painless range of motion and had no recurrence except four patient. One is type IIIa Bankart lesion in which associated type II SLAP was not repaired and the other two patients had sport injury and one patient had severe retrauma on 2 years after operation. We conclude that Bankart lesion is the essential lesion of recurrent anterior shoulder instability and were founded in all cases of recurrent anterior shoulder instability, and modified athroscopic transglenoid suture capsulorrhaphy according to arthroscopic classification is safe and effective method with acceptable recurrence rate.