Efficacy and Safety of Levamlodipine Besylate Compared to Amlodipine Maleate in Patients With Essential Hypertension

Inclusion Criteria: * Male or female outpatients, 18-75 Years * Patients with mild to moderate essential hypertension (defined as mean BP of 2 visits ≥140mm/90mmHg, and \< 180mm/110mmHg) * Written informed consent Exclusion Criteria: * Patients with secondary hypertension * Patients with severe hypertension * Have to take other drugs that can influence blood pressure during the study * Allergic to DHP calcium antagonists * Evidence of congestive heart failure, unstable angina or severe arrhythmia * Renal or hepatic dysfunction * Women who are taking contraceptive pills or are likely to be pregnant * Participate in other clinical trials within 3 months prior to this study