Inclusion Criteria:  Age ≥70 years old; Symptomatic severe aortic stenosis determined by echocardiogram, defined as: mean gradient ≥40 mmHg or peak jet velocity ≥4.0 m/s, or an aortic valve area <0.8 cm2 or aortic valve area index <0.5 cm2/m2. NYHA Functional Class ≥II; Life expectancy after aortic valve implantation thought to be >1 year; Native valvular or peripheral vascular anatomy is appropriate for TAVR; Patient is assessed by at least two cardiothoracic surgeons and recorded as not suitable for surgery; Patient can understand the purpose of the study, voluntarily participates and signs the informed consent form and is willing to accept the relevant examination and clinical follow-up visits.  Exclusion Criteria:  Anatomy is not appropriate for percutaneous valve implantation. Native valve annulus diameter is not in the scope of application(native TAV diameter ≤21mm, or ≥30mm); Evidence of an acute myocardial infarction within 30 days prior to the study procedure, defined as: Q-wave myocardial infarction, or non-Q-wave myocardial infarction, with CK-MB≥2 ULN/or elevated TN (WHO definition); Any treatment for traumatic cardiac surgery within 30 day prior to the study procedure(except coronary revascularization); Pre-existing prosthetic valve in any position(except severely dysfunctional aortic bioprosthesis), or severe (>3+) mitral insufficiency, or Gorlin syndrome; Hematological abnormality, defined as: Leukopenia (WBC <3x10^9/L), acute anemia (Hb <90g/L), or thrombocytopenia (platelet count<50×109/L),history of bleeding diathesis or coagulopathy; Hemodynamic unstable requiring myocardial contractile support or mechanical cardiac assistance; Severe ventricular insufficiency. Left ventricular ejection fraction (LVEF) <20%; Echocardiographic evidence of intra-cardiac thrombus or vegetation etc.; Active pepticulcer or upper GI bleeding within 3 months prior to the study procedure; Cerebral Vascular Accident (CVA) within 3 months prior to the study procedure, including TIA; A known hypersensitivity or contraindication to aspirin, heparin, ticlopidine or clopidogrel, or sensitivity to contrast media, which cannot be adequately pre-medicated; Patients with infective endocarditis or other active stage of infection; Currently participating in an investigational drug or another device trial.