Effect of Nifedipine GITS in Patients With Mild-to-moderate Primary Hypertension

Inclusion Criteria: * a seated systolic BP (SBP) ≥140 mmHg and \<180 mmHg and/or a seated diastolic BP (DBP) ≥90 mmHg and \<110 mmHg; * an age ≥18 and ≤75 years; * those who had not taken any BP-lowering medications in 1 month before the study. Exclusion Criteria: * a seated systolic BP (SBP) ≥180 mmHg and/or a seated diastolic BP ≥110 mmHg; * secondary hypertension; * diagnosed heart failure or stroke; * Any of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) was above 1.5 times of it's normal value upper limit, Serum creatinine \>177 µmmol/L (2mg/dL), or liver cirrhosis; * subjects with carotid stenosis or systolic murmur * subjects with a history of unstable angina pectoris, acute mycardial infarction, percutaneous transluminal coronary angiography or coronary artery bypass grafting in the past 6 months; * subjects who were within lactation period, pregnant, or planning to become pregnant during the study; * hypersensitive to Nifedipine GITS or with SAE; * subjects who are participating in other clinical trials; * considered not fit for the study due to other reasons according to the researchers (such as Malignant tumor, psyche or nervous system dysfunction, or special diseases).