Abstract: Objective: To investigate the risk factors influencing mortality in traumatic diaphragmatic hernia (TDH) or diaphragmatic injury. Methods: Collecting the clinical data from the 51 patients admitted with TDH or diaphragmatic injury, and a contrast study was performed for exploring possible risk factors among 12 variables in the survival group and the death group by using statistic analysis. Results: Nine of fifty-one patients died and mortality was 18%, 4 patients died of hemorrhagic shock at early stage (<24 h ) and 5 patients died of postoperative sever complications, including sever infections and ARDS (n=2)，sever infections(n=1), ARDS（n=1）and MODS (n=1). Age, injury serverity score(ISS), volume of transfusion in perioperative period，on admission in shock，postoperative complications，systolic pressure and spleen injury scale etc 7 factors were different statistically between the two groups（both P<0.01）by statistics analysis. Logistic regression analysis demonstrated that volume of transfusion during perioperative period≥1 400 mL（OR=41） and spleen injury scale≥Ⅲ(OR=74) were both the independent predictors for mortality in TDH or diaphragmatic injury (P<0.05～0.01). Conclusion: Sever associated injuries preoperatively especially sever splenic injury，bleeding too mach during perioperative period and sever complications postoperatively prompt bad prognosis in TDH or diaphragmatic injury patients.