OBJECTIVE: To investigate the curative effects of Xuebijing(XBJ) injection, a Chinese patent medicine, on severe pulmonary contusion(PC). METHODS: Sixty-three patients with PC were randomized to conventional therapy plus XBJ injection(n=33) or conventional therapy alone(n=30). Between groups differences in corticosteroid treatment, immune regulation therapy, hemofiltration, infusion volume, transfusion volume and antibiotic period were measured, as were intensive care unit (ICU)-free time, ventilation time, 28-day mortality rate and incidence of ventilation-associated pneumonia(VAP). Serum concentrations of procalcitonin(PCT), tumor necrosis factor-α(TNF-α), interleukin(IL)-6, and IL-10, white blood cell(WBC) counts and percentages of human leukocyte antigen DR/ CD14+(HLA-DR/CD14+) peripheral blood mononuclear cells were compared. Markers of ventilation were determined by blood gas analysis and ventilator parameters. RESULTS: WBC counts and serum concentrations of PCT, TNF-α, IL-6 and IL-10 were reduced significantly more quickly, and CD14+ percentage was increased significantly earlier, in the XBJ group than in the control group(P< 0.05). XBJ treatment significantly reduced ICU-stay time, ventilation time and incidence of VAP(P0.05). CONCLUSION: XBJ treatment can shorten ICU-free and ventilation times and reduce the incidence of VAP, improving outcomes in patients with severe PC. XBJ may act by regulating inflammation and immunity, alleviating systemic inflammatory response syndrome induced by trauma.