• Severe mitral regurgitation≥3+ (moderate or above degenerative mitral regurgitation disease, or with stenosis is included);

• Age≥70 years; or patients who are 60\

⁃ 70 years old, and the STS risk score indicate that participants are at high risk of traditional surgery or cannot tolerate traditional thoracotomy;

⁃ 4\) Left ventricular ejection fraction≥30%； 5) As assessed by multidisciplinary cardiac team (at least two cardiac surgeons/one cardiologist), patients who are at extremely high-risk or unsuitable for routine mitral valve surgery with evaluation; 6) Patients who understand the purpose of the trial and volunteer to participate in, sign the informed consent form and are willing to accept relevant examinations and clinical follow-ups.

⁃ Anatomy selection Criteria：

• The regurgitant jet of mitral valve originates from the A2 and P2 (the lesions of A2/P2 in mitral valve causes regurgitation);

• The width of the mitral valve prolapsed area is ≤15mm, Height of Prolapse ≤10mm or coaptation depth≤11mm, coaptation height≥2mm, effective length of anterior and posterior leaflets\>1cm (conforming to EVEREST II recommended mitral valve interventional edge-to-edge repair standards);

• Effective mitral valve orifice area≥ 4.0cm2;

• No obvious calcification of the mitral valve annulus and valve leaflets;

• Patient's anatomical conditions allow transseptal approach.