Abstract： Objective To investigate the early changes of plasma levels of angiopoietin2 in patients with multiple trauma and the relationship between plasma levels of angiopoietin2 (Ang2) and endothelial injury as well as prognosis of patients in order to determine their clinical significance. Methods Patients with multiple trauma admitted to emergency department from January 2008 to January 2010 were enrolled. A total of 59 casualties met the criteria(admission within 1 h after trauma and age > 18 years), and were eligible for enrollment. Patients with heart, brain, liver, kidney and other organic diseases, diabetes, hypertension, tumor, acute and chronic infectious diseases , severe brain injury (CCS < 12 points) , anticoagulant and thrombolytic medicine used two weeks before trauma were excluded. Among 59 patients, 36 were males and 23 females. The average age was(32.3 ±11.5) years. Patients were divided into severe trauma group (ISS ≥16 points,n =29) , moderate trauma group (ISS < 16 points, n =30 ) judged by using injury severity score (1SS). Thirty healthy subjects were selected as controls, 19 male and 11 female, with age > 18 years and an average age of(33.5 ±10.6) years. All groups had comparable gender proportion and average age. The 10 mL peripheral blood sanple was collected within 10 minutes after arrival of patients to emergency department and the plasma was separated from blood. Enzyme-linked immunosorbent assay (ELISA) was used to detect the plasma levels of angiopoietin2, and the plasma levels of von Willebrand factor (vWF) and thrombomodulin (TM) were also detected. Data were expressed as mean ± standard deviation and were statistically analyzed by using SPSS version 13.0 statistical software. The differences in plasma levels of angiopoietin2 of patients in each group were analyzed by ANOVA and Newman-Keuls test. Levels of angiopoietin2 in fatal patients and survival patients were also compared by using t test. The relationships between angiopoietin2 and plasma levels of vWF as well as levels of TM were analyzed by Pearson correlation analysis. Changes were considered as statistically significant if P value was less than 0.05. Results The plasma levels of angiopoietin2 in severe trauma group (ISS scored 16 points) were significantly higher than those in moderate trauma group (ISS < 16 points) ( P < 0.05 ), and those in trauma patients of the two groups were both significantly higher than those in control group (P < 0.05). The plasma levels of angiopoietin2 in fatal patients were significantly higher than those in survivors (P < 0.05). Plasma levels of angiopoietin2 were significantly correlated with plasma levels of vWF and TM (P < 0.05). Conclusions The plasma levels of angiopoietin-2 significantly increase after multiple trauma, and correlate with the degree of trauma severity. The plasma levels of angiopoietin2 correlate with endothelial injury after multiple trauma, having important prognosis value in patients with multiple trauma.