This research is aimed to discover the influence and underling mechanism of combined infusion of arginine vasopressin with levosimendan on acute lung injury in rat septic shock with norepinephrine supplemented. The traditional fecal peritonitis-induced septic shock model was undergone in rats for study. It is observed that the combined infusion supplemented with norepinephrine brought about a lower mean pulmonary artery pressure; lower high-mobility group box 1 levels, pulmonary levels of interleukin-6, and arterial total nitrate/nitrite; lower apoptotic cells scores and total histological scores; but higher pulmonary gas exchange when compared with the separate infusion group and norepinephrine group. This therapy shows potential clinical beneficial assistance in sepsis-induced acute lung injury. The results suggest the mechanism of such effect is through abating pulmonary artery pressure, and more importantly suppressing inflammatory responses in lung when compared with norepinephrine infusion group and the separate infusion of levosimendan or vasopressin alone.