Abstract: Objective To investigate the aggregation of sodium sensitivity and positive to cold pressure test among siblings.Methods By prescreening and twice blood pressure screening,163 probands and siblings were selected,including 49 sibships with 2 siblings and 19 sibships with 3 and more siblings.All siblings undenvent chronic sodium load test and cold pressure test.Results 21.5% of participants were observed to be salt-sensitive Siblings being salt sensitivewere proved to be clustered among sibships with 3 and more siblings (χ²=19.88,P<0.O1).The changing of blood pressure and urinary sodium excretion between siblings were positively correlated 25.15% of the participants positively reacted to cold pressure test which was also proved to be clustered among sibships with either 2 or 3 siblings=6.678,P<0.05; χ²=10.615,P<0.05).The changing of blood pressure and recovery tine were correlated positively among siblings.Conclusion Binom final distribution analysis showed that salt-sensitive and positive to cold pressure test clustered among siblings,which might attribute to the hereditary factor but not environment effects.