Objective To explore the risk factors for deep vein thrombosis in patients with traumatic brain injury.Methods 362 head injury patients were checked by vascular ultrasound in 10,20,30,40,50 days after injury, when DVT was diagnosed, they were treated immediately.The relevance of age, illness, time of lying, sex and the DVT was analyzed.Results 48 patients 63 legs had DVT.DVT incidence rate was 17.50%(28/160) in high blood pressure(HBP) patients,and 9.90% (20/202) in no HBP; 10.71%(33/308)in lower 60 years old patients, 27.78%(15/54)in higher 60 years old; 25.0%(21/83)in diabetes patients,9.68%(27/279) in no diabetes patients; 22.92%(44/192) in paralytic legs,3.57%(19/532) in no paralytic legs; 2.21%(8/362) in patients of lying in bed for 10 days,7.46%(17/228) for 20 days,12.12% (24/198)for 30 days,24.43%(32/131) for 40 days,39.1% (43/108)for 50 days.Conclusions DVT incidence rate in patients with TBI may be correlated with age, HBP, diabetes, leg activity, the time lying in bed.Eld, HBP,diabetes, paralytic leg, longer than 10 days lying in bed are all risk factors to generate DVT.