Abstract: Fifty-five cases aged 4~5 year old healthy children were divided into two groups. group A （n = 34 ） male 16.female 18, and group B （n = 21 ）, male 8. female 13. Bothgroups took conventional diet and blood pressure, height.weight and heart rate were measured, 24 hour urine was collected for measuring Na,K,Ca and creatininc. During the first6 months, group A took a diet with sodium restricted to 50mmol and calcium gluconate 1. 5 g per day. Group B took regular diet without sodium restriction and calcium supplernent.The above examinations were repeated after six months, then,the diet pattern crossed over, and followed for another 6months and the examinations were repeated at the end of investigation. It was shown that the SBP. DBP, mean BP ingroup A were significantly decreased after 6 months sodium restriction and calcium supplementation. but BP restored to evenhigher level after 6 months regular diet. In group B when urinary sodium was stable, the calcium supplementation did notproduce any BP lowering effect. No difference in urinary calcium excretion in either group during the whole study period hadbeen found.