Abstract: Objective To evaluate the application of Duncan loop sliding knot in patients with shoulder instability. Methods Arthroscopic procedures were performed for shoulder instability using suture anchors and capsular overlapping techniques.Shoulder instability was fixed with Duncan loop sliding knots.Patients were evaluated with UCLA,Constant,Rowe,and VAS scoring systems. Results A total of 15 cases were followed up for an average time of 13.4 months.Arthroscopic Duncan loop sliding knots were used 54 times.Apprehension,Sulcus,and anterior drawer tests were negative.X ray revealed the satisfactory positions of suture anchors with no herniation at the last follow-up.Significant improvement was found in UCLA,Constant,Rowe,and VAS scores after operation. Conclusion Duncan loop sliding knot can effectively fix shoulder instability.