A novel barbed suture comprises improved retaining strength or anchoring ability within the tissue in both directions of the suture. The barbed suture of the present invention comprises a plurality of barbs which are made of filaments. The ends of the filaments are attached to the main body of the suture thread to form barbs. The barbs are flexible and allow tissue ingrowth. As a result, the barbed suture is allowed to be readily deployed in the tissue with high retaining strength in both directions of the suture. The retaining strength enhances the barbed sutures ability to hold tissue together with improved wound closure or tissue approximation performance.