Abstract: In this study of 310 school children, an oral saline load test was performed. Plasma insulin and the related parameters were measured. All the children in this study are from Hanzhong’ south of Shan’xi, aged 10 15, grouped into higher vs normal blood pressure,with or without hypertension family history（FH）. All the groups are matched for their sex and age,and followed up for 5 years. In the children with their systolic blood pressure on higher percentiles and with FH+, the plasma insulin was significantly higher than that in their respective control group. In children with the plasma insulin level equal to or greater than the 75th percentiles （≥P75 ）. The RBC-Na/Li counter-transport rate was accentuated, the systolic blood pressure increment and 6 hour urinary soc1ium excretion after salt load were greater than those in the ≤P50 group. It is suggested that insulin resistance is associated withsalt-sensitivity, which may play a role in the development of hypertension in childhood.