Objective To study the role of hemorrhagic shock in severe eraniocerebral trauma with stress ulcer.Methods The clinical data of 428 patients of sevcere craniocerebral tramna in 0111"hospital from January 2001 to January 2009 were divided into two groups according to whether or not merging with hemorrhagic shock.The incidence of stress ulcer in two groups was calculated and the PH ofgastric juice and blood in different periods were measured.Results Stress ulcerdevelopedin 56.4%(75/133)ofpatientswith hemorrhagic shockand 12.5%(37/295)of patients with hemorrhagic shock-free,with significant difference between the two groups(P＜0.01).Blood pH differed significantly(P＜0.01)on 2d,but not on 7d(P＞0.05)after injury between the two groups.There wag no significant difference in gastric juice pH on 2d and 7d after injury between the two groups(P＞0.05).Condusion Hemorrhagie shock phys an important role in severe craniocerebral trauma with stress deer.