Inclusion Criteria:  Age: 30-50 Years; Sex: All; Alport syndrome patients with variants of COL4A3/COL4A4/COL4A5; hematuria or microalbuminuria; eGFR>90 mL/min/1.73m2; Patients with microscopic hematuria only; Patients with microscopic hematuria and microalbuminuria: 30-300mg/24h or urine albumin/creatinine: 30-300mg/g; No angiotensin converting enzyme inhibitor (ACEI) and other renin-angiotensin system inhibitors (including angiotensin II receptor antagonists, etc.) treatment.  Exclusion Criteria:  With primary or secondary kidney disease, including IgA nephropathy, membranous nephropathy, lupus nephropathy, benign renal arterioles, etc.; Patients with a history of angioedema; Hypovolemia or hypotension (systolic blood pressure less than 90mmHg and/or diastolic blood pressure less than 60mmHg); Pregnant and lactating women; Patients with bilateral renal artery stenosis or unilateral renal artery stenosis with solitary kidney; Hyperkalemia, blood potassium>5.5mmol/L; Severe aortic stenosis, severe mitral stenosis; Treatment of drug allergy; Hypertension or other diseases that may require treatment with angiotensin-converting enzyme inhibitors; Disagree to participate in this research.