Subjects must meet all of the following criteria to be included in the study:
* Subject has symptomatic, moderate-to-severe or severe, degenerative mitral regurgitation(MR≥3+);
* NYHA functional class≥ II;
* Heart team agrees that patient is unsuitable for treatment with conventional mitral valve surgery or transcatheter mitral valve edge-to-edge repair；
* Subjects age ≥65 years old;
* Subjects willing to sign Informed Consent for participation in the study and return for all required post-procedure follow-up visits;
* Subjects anatomically suitable for the transcatheter mitral valve implantation
Subjects will be excluded from the study if any of the following conditions are present：
* Left ventricular ejection fraction (LVEF)\<30%；
* Left ventricular end diastolic diameter (LVEDD)\>7.5cm；
* Cardiac echography evidence of intracardiac mass, thrombus, or vegetation；
* Severe tricuspid regurgitation with severe right ventricular dysfunction or any tricuspid valve disease requiring surgery or transcatheter intervention；
* Aortic valve diseases requiring surgery or transcatheter intervention；
* Any prohibitive mitral annular calcification(annulus to the leaflet) interferes the expansion of the device；
* Prior surgical treatment of mitral valve；
* Therapeutic cardiac surgical or interventional procedure within 30 days prior to the index procedure；
* End-stage heart failure requiring left ventricular assist device or cardiac transplantation
* Subjects with severe major vascular disease requiring surgical intervention or with aortic dissection
* Need for emergent surgery
* Hypertrophic or restrictive cardiomyopathy, constrictive pericarditis
* Mitral valve pathological anatomy，LVOT anatomy, left atrial or ventricle anatomy not applicable for the investigational device implantation；
* Concurrent medical condition with a life expectancy of less than 12 months
* Evidence of an acute myocardial infarction or untreated clinically significant coronary artery disease requiring revascularization within 30 days of enrollment.
* Recent cerebrovascular events(ischemic or hemorrhage stroke, not including TIA) within 3 months of enrollment
* Severe carotid stenosis( \> 70%, both sides of carotid artery)
* Any of the following: leukopenia, acute anemia, thrombocytopenia, history of bleeding diathesis, or coagulopathy if cannot be adequately treated；
* Active endocarditis or active other infection
* Active peptic ulcer or history of upper gastrointestinal bleeding within 3 months
* Subject refuses the blood transfusion;
* Known hypersensitivity or contraindication to nitinol (titanium or nickel),bovine product, PET(Polyethylene terephthalate), contrast media; Inability to tolerate anti-platelet or anticoagulants therapy; Contraindicated for transesophageal echocardiography (TEE)
* Condition that prevents transapical access, such as chest malformation, ventricular aneurysm, apical thinning
* Subjects with rheumatic mitral stenosis
* Acute exacerbation of chronic obstructive pulmonary disease
* Per heart team assessment, conditions that not suitable for transcatheter mitral valve replacement
* Severe disabling Alzheimer's disease
* Currently participating in an investigational drug or another device study that has not yet reached its primary endpoint
