This study is a single arm trial with before-after comparison design. Three groups of patients with hypertension will be recruited: not taking antihypertension drugs and having normal renal function, taking antihypertension drugs and having normal renal function, and having abnormal renal function without regards of antihypertension drugs use. Each group includes 30 patients. Based on renal function test, the investigators provide the Manlikang containing potassium chloride to patients with normal renal function, and provide the Manlikang not containing potassium chloride to patients with abnormal renal function. All hypertension patients will use the formula salt with very low sodium (Manlikang) for six weeks, and will be followed up at 1, 2, 4 and 6 weeks. The primary outcome will be the decrease of patients' systolic blood pressure at the end of the trial.

Inclusion Criteria:

• 50 to 75 years old
• No planning to move out of the community in the next three months
• Not cooking at home less than 3 times or one day during the study
• Willing to participate in the study and sign informed consent

Exclusion Criteria:

• Acute myocardial infarction, history of stroke in the past 3 months, history of malignancy or expected lifetime less than 1 year.
• Hypercortisolism or aldosteronism
• Acute disease, such as upper respiratory infection, fever and diarrhea.
• Incapable of communicating, such as deaf and dumb, dementia, mental disorder.
• Families taking salt substitute currently
• Not willing to use Manlikang in family
• Liver disfunction
• Anyone with abnormal serum potassium in family
• Anyone using potassium-retaining diuretics in family