Abstract: Acute lung injure (ALI) is a severe diffused lung disease, which is caused by pathogen-induced infections, inhalation of irritates, and so on. It could lead to acute respiratory distress syndrome (ARDS). Long oil (LO) is a lipidic mixture extracted from multiple medicinal animals and plants. It has been used for clinical wound repair. Here, an O/W LO emulsions (LOE) was prepared, which was composed of LO, Tween-80, propylene glycol, xanthan gum, and water. The droplet size of LOE was 671.63 ± 7.21 nm, and the zeta potential was-17.8± 1.26 mV. The size of LOE was small and homogenous, and the stability was satisfied. The aerosols had an aerodynamic diameter of 2.25 ± 0.05 μm after atomization of LOE with a vibrating screen atomizer, where the percentage of particle sizes within 1-5 μm was 81.40%, indicating effective deep lung deposition and suitable pulmonary inhalation. The safe dose of LOE was high to 12.50 μg·mL^-1 on human embryonic lung fibroblast MRC-5 cells. In the range of 0.02-2.50 μg·mL^-1 of LOE, the proliferation and migration of mouse fibroblast L929 cells were improved. Animal experiments were approved by the Ethics Committee of Institute of Radiation Medicine, Academy of Military Medical Sciences, and the experiments were conducted by relevant guidelines and regulations. No significant toxicity was observed after intratracheal (i.t.) administration of LO (3.25 mg·kg^-1) to mice. Mouse i.t. administration of LOE remarkably attenuated lung injury induced by lipopolysaccharide with mitigations of inflammatory factors (tumor necrosis factor-α, interleukin-6) and total proteins. LOE is a promising inhaled formulation for the treatment of ALI.