Abstract: OBJECTIVE: To investigate the effect of mannitol on early hematoma expansion in hypertensive cerebral hemorrhage and how to use mannitol correctly. METHODS: One hundred and twenty hypertensive patients, all with supratentorial non-thalamic hematoma and mild impairment of consciousness, were selected; those with hematoma volume ≥5O ml and those with severe cardiac, hepatic and renal system diseases were excluded and randomly divided into three groups. Results: The difference between the conventional group and the other two groups was significant (P0.05). 25 cases of hematoma enlargement in 120 cases, accounting for 20.83%. the efficacy assessment of the three groups of patients on the 15th day of treatment was 57.5% in the conventional group; 77.5% in the observation group; and 80.0% in the control group. The difference between the conventional group and the observation group and the control group was significant (P35%) in 18 cases (45.0%), 5 cases (12.5%) in the observation group and 3 cases (7.5%) in the control group. The difference between the conventional group and the other two groups was significant (P0.05). 120 cases of hematoma enlargement 25 cases (20.83%). 2.2 Neurological symptoms of the 3 groups within 6h of the onset of CT examination were not severe headache, vomiting and consciousness disorder and other obvious intracranial pressure increase; 48h CT examination of the conventional group appeared severe headache and other intracranial pressure increase, the observation group did not appear the above symptoms, the control group patients had moderate headache. 2.33 The efficacy assessment of patients in the 15th day of treatment was 57.5% in the conventional group; 77.5% in the observation group; and 80.0% in the control group. The difference between the conventional group and the observation group and the control group was significant.