Inclusion Criteria:  Severe aortic valve stenosis, defined as follows:  Symptomatic patients:  The mean differential pressure measured by echocardiography ≥ 40mm Hg Or peak aortic ejection ≥ 4.0 m / S Or aortic valve area ≤ 1.0cm ²（ Or AVA index ≤ 0.6 cm2 / m2)  Asymptomatic patients:  Severe aortic stenosis and aortic valve area ≤ 1.0cm ²（ 6 cm2 / m2) with aortic ejection peak value ≥ 5.0 M / s or mean pressure difference measured by --echocardiography ≥ 60 mm Hg; Or aortic valve area ≤ 1.0cm ²（ Or AVA index ≤ 0.6 cm2 / m2), combined with aortic ejection peak ≥ 4.0 m / s or average differential pressure measured by echocardiography ≥ 40 mm Hg, combined with limited exercise tolerance test, abnormal blood pressure response or arrhythmia; Or aortic valve area ≤ 1.0cm ²（ Or AVA index ≤ 0.6 cm2 / m2), combined with aortic ejection peak ≥ 4.0 m / s or average differential pressure measured by echocardiography ≥ 40 mm Hg, combined with LVEF < 50% Subjects who plan (or have) to use the transcatheter aortic valve replacement system for percutaneous aortic valve replacement The patients agreed to join the study, voluntarily signed the informed consent and completed the follow-up; Be able to contact the subjects or their legal guardians / relatives; The medical record records the subjects who have died and can't get any contact information of the subjects（ (for dead cases only)  Note: for dead subjects, they must meet 1, 2 and 5 at the same time before they can be included in the group.  Exclusion Criteria:  Contraindications to any artificial biological valve implantation;  Any known allergies or contraindications;  Aspirin or heparin and bivalirudin; Tigrelol and clopidogrel; Nickel titanium alloy; Contrast medium; The patient is currently participating in drug or device research; The patient is pregnant or lactating; Aortic annulus diameter < 17 mm or > 32 mm; The diameter of approach vessel was less than 5.0mm; The investigator believes that the patient is not suitable to participate in this study or complete the follow-up specified in the protocol;