Abstract: Objective To explore the significance of sodium levels in evaluation of prognosis of patients with severe stroke combined with acute kidney injury （AKI）. Method Electrolytes and renal function of different periods after hospitalization were detected in 300 patients with severe strokefrom Jan.2012.1 to Dec.2014. with,The patients were scored with APACHEⅡ,followed by administration of the symptomatic treatments. Results Sixty of 300 patients were found to present high hyponatremia ,accounting for 20.0%; 44 （14.67%）cases had AKI,Eighteen of 60 high hyponatremia patients revealed acute cerebral infarction,32 had acute cerebral hemorrhage,and 10 possessed subarachnoid hemorrhage. The average measurement score of APACHEⅡ was （24.5 ± 6.4）; AKI was noted in 17 cases（28.33%）,The high serum sodium concentration was in parallel with the high frequencies of AKI occurrence. Conclusion In patients with severe stroke combined with acute renal injury,hypernatremia usually happens 3-7 days after the disease. A high sodium level which occurs 7 days after disease may indicate a poor consequence of treatment and a high mortality

Key words: Sodium ion levels, Stroke, Acute kidney injury