FIELD : medicine.SUBSTANCE : invention relates to medicine, particularly to cardiovascular surgery. Autologous transplant used is chemically untreated tendon of plantar muscle (TPM), for which it is pre-sampled. Under conditions of artificial blood circulation and cardioplegia access to mitral valve (MC), mitral valve inspection is performed, fibrous ring (FR) MC U-shaped poly-filament sutures on gaskets from autopericardium with prickings from left atrium. MC flaps are reconstructed, both ends of thread are sutured through thickness of tendon with pricks in direction of valve flap, receding from end of tendon. Second edge of the suture is fixed with a spacer from autopericardium, thread ends are tied. Cloth closure is performed auto-tendon fixing TPM nodal poly-filamentous sutures by means of edge suturing auto-tendon with endocardium in zone FR single-row continuous coined monofilament suture.EFFECT : method enables minimizing a risk of postoperative complications.4 cl, 1 ex