The sustained reduction in elevated blood pressure and lower incidence of adverse events of Lacidipine may provide additional benefits for hypertension patients than other CCBs (calcium channel blockers). This study is to compare the efficacy and safety of Lacidipine with Amlodipine, the most widely used CCB in Taiwan, in hypertensive patients.

Inclusion Criteria:

• Informed consent written prior to the recruit into the study
• Male or female subjects
• Patients with diagnosis of essential, uncomplicated hypertension
• After one to two weeks washout period, patients showing, systolic blood pressure equal or lager than 160mmHg or diastolic blood pressure equal or lager than 90mmHg

Subject could be enrolled in one of the following state:

1. Patients previously untreated for hypertension;
2. Intolerant or not responding to their current therapy;
3. Patients controlled under their previous therapy but who can safely and agree to be switched to the trial therapy could clinically feasible for mono-therapy for hypertension control.

Exclusion Criteria:

• Any form of secondary hypertension
• History of malignant hypertension or evidence of accelerated hypertension
• Myocardial infarction within 3 months
• Unstable angina pectoris
• Congestive heart failure
• Atrial fibrillation
• Life threatening arrhythmia
• History of cerebrovascular accident
• Clinically relevant renal disease; defines if serum creatinine equal or lager than 1.5 mg/dl
• Liver function abnormal: glutamic-oxalacetic transaminase lager than 2 times of upper limit normal or glutamic-pyruvic transaminase lager than 2 times of upper limit normal
• Existence of any serious systemic disease
• Allergic history to the compounds of both study medication
• Can not comply the study protocol or misunderstand the informed consent form
• Other diseases which treated by calcium channel blockers