The present invention relates to a device for mitral valve cerclage which is used on mitral valve cerclage patients with mitral regurgitation and the device safely and effectively transfers and maintains the final appropriate tension required for cerclage. The device for mitral valve cerclage of the present invention for protecting the tissues of the coronary sinus and the tricuspid valve and for delivering a knot to maintain the tension of a cerclage string comprises: (A) a tissue protective device (20) comprising a tube for the coronary sinus (22) which is a hollow cylindrical tube for protecting the tissue of the coronary sinus a tube for the tricuspid valve (24) which is a hollow cylindrical tube for protecting the tissues of the tricuspid valve and the ventricular septum and a stalk portion (26) in which the tube for the coronary sinus and the tube for the tricuspid valve are extended to be fixed and combined to each other and (B) a knot delivery device (30) which is a hollow catheter and has an openable/closable open/close portion (32) at one end and a through hole (34) formed longitudinally at a lateral side of the open/close portion.
