Objective To testify the efficacy of revised trauma score （RTS） in evaluating the severity of trunk injury，analyze its inadequacy and make modifications to improve its specificity and accuracy in evaluating trunk injury. Methods Medical records of 278 patients undergoing emergency surgery for the treatment of trunk injury in West China Hospital of Sichuan University between January 2006 and June 2012 were retrospectively analyzed. There were 231 males and 47 females in the age of 1-75 （33.7±14.1） years. RTS was calculated for each patient. Hemoglobin （Hb） concentrations in these patients acquired at the emergency room were included to reflect the severity of blood loss. The correlations between RTS and patient response to treatment as well as RTS and prognosis were analyzed. Patient response to treatment and prognosis were compared between the normal RTS group and the abnormal RTS group. Univariate analysis was performed followed by multivariate analysis for the variables which may impact prognosis. Modified RTS was established by regression analysis. Results RTS was significantly correlated with patient response to treatment as well as prognosis. RTS was significantly correlated with the time duration between the onset of injury and the beginning of operation （r =0.249，P＜0.001）， thoracic and abdominal blood loss volume （r = -0.255，P＜0.001），fluid resuscitation volume （r = -0.244，P＜0.001） as well as length of ICU stay （r = -0.202，P=0.001）. Mortalities in patients with different RTS were statistically different （P=0.004）. In the patient group with normal RTS the mortality was 5.1%，which indicates the inadequacy of RTS in evaluating trunk injury. Univariate analysis revealed that both emergency room Hb and RTS were correlated with patients’ prognosis. After putting these two factors into the regression analysis，a new formula to calculate modified RTS is established：Logit （P death）=6.450-0.769×RTS-0.029×Emergency room Hb. Conclusion Modified RTS is more specific in evaluating trunk injury and maintains the advantages of simplicity and rapidness.