Hypematremia was defined as a rise in the serum sodium concentration to a value exceeding 145 mmol per liter. A prospective observational performed on 21 severe burns patients at ICU of National Institute of Burn. The clinical symptoms related to the syndrome of hypernatremia, the relevant factors and treatment outcome of hypematremia were analyzed. The results showed that: hypematremia patients with total bum surface area 60 +/- 17,2 percent, occurs after 9.14 +/- 4.8 days of hospitalising, the risk factors were related inhalation bum injury (accounted for ,47.6 percent) and 90.47 percentpatient with machenical ventilation. The SOFA score of the patients at the time of hypermatremia was 11. Mortality rated of hypematremia patients was 95.23 percent.