Objective To explore the effects of low-sodium salt on blood pressure and to find out an economical,effective and easy-to-implement method to reduce the blood pressure.Methods This study was a randomized controlled study based on family unit.The participation families were recommended by local newspaper reporters and each family included at least 2 family members over 50 years old,who composed the objects of the study.The intervention group received two-month salt substitution intervention (with low sodium and high potassium) for free,while the control group received no intervention.Results The decrement of systolic blood pressure in intervention group was (4.7±10.9)mmHg,while the systolic blood pressure in control group was decreased by (2.6± 10.3)mmHg.The decline range of blood pressure was higher in the intervention group than in the control group,and there was a statistical significance in the difference (t=2.19,P＜0.05).Conclusions Salt substitution (with low sodium and high potassium) is an economical,effective and easy-to-implement method to reduce the blood pressure.Therefore,it is recommended to promote salt substitution (with low sodium and high potassium) in the crowd.