Abstract: Objective To determine the incidence of sodium disorder in the moderate-severe traumatic brain injury patients and its association with the location of intracranial hematoma and mortality of patients. Methods A total of 452 patients faced moderate and severe traumatic brain injuries diagnostic criteria in our hospital from January, 2014 to May, 2017 were enrolled into this study. The patient's general information was recorded after admission. All the patients underwent cerebral computed tomography to locate intracranial hematoma and received GCS. The serum sodium level immediate after admission and duration the stay in hospital, the degree of conscious disturbance and mortality were as research variable. SPSS 20.0 was used to analyze the relationship between the incidence of sodium disorders and the location of intracranial hematoma and mortality. Results The incidence of sodium disturbances was 45.1%(204/452):128 patients were with hypernatremia and 76 with hyponatremia. Sodium disturbances were detected in the first sample in 50% of the patients. The serum sodium level in 50% of the patients with hyponatremia was less than 125 mmol/L by a series of tests. There was significant difference in the incidence of sodium disorders among the patients with different location of injury (P<0.5). The patients who got subdural hematoma, the brain hematoma and diffuse axonal injury would have a better chance of sodium disorders. The mortality of patients with abnormal blood sodium was higher than that in the normal group. Conclusion The incidence of sodium disorder in the moderate-severe traumatic brain injury patients is higher, especially in the patients get a subdural hematoma, brain hematoma and diffuse axonal injury. Abnormal blood sodium may be associated with mortality.