Objective To study the best position for children to transfusing mannitol by venous, and then reduce the incidence rate of complication. Method Divided children into 3 groups according to the injection point. There were 69 cases in the A group, the injection points included cephalic vein, basilic vein, median cubital vein and the external jugular vein. There were 46 cases in the B group, the injection points included vein of forehead, superficial temporal vein and the posterior auricular vein. There were 63 cases in the C group, the injection points included dorsal vein. Results The condition of transfusing mannitol by venous in the A group were significant better than those of in the B and C group,P