Abstract: Objective：To investigate the protective effect of 15d-PGJ2 treatment on a rat model of combined acid and gastric particles (CAGP)-induced aspiration lung injury. Methods：The model of CAGP-induced aspiration lung injury model was established in SD rats. Twenty SD rats were randomly divided into control group and experimental group, with 10 rats in each group. Control group: rats were treated with CAGP intratracheal instillation and PBS intraperitoneal injection; experimental group: rats were treated with CAGP intratracheal instillation and 15d-PGJ2 intraperitoneal injection. At 4 h and 12 h after CAGP instillation, the arterial partial pressure of oxygen (PaO2), wet-to-dry weight ratio (W/D) of lung tissue, total protein concentration in bronchoalveolar lavage fluid (BALF), white blood cell count and differential count in BALF, tumor necrosis factor-α (TNF-α) concentration in BALF and serum, and lung inflammation score by H&E staining were analyzed in samples of 5 rats from each group. Results：Compared with control group, inflammatory scores based on histology were alleviated, and PaO2 was improved at 4 h and 12 h after CAGP injury in 15d-PGJ2 treatment group. Compared with control group, W/D of of lung tissue, total protein concentration in BALF, white blood cell count and differential count in BALF, TNF-α concentration in BALF and serum were decreased at both timepoints in 15d-PGJ2 treatment group (P<0.05). Conclusions：15d-PGJ2 could alleviate the levels of lung injury and inflammation, and improve the PaO2 in rat CAGP-induced aspiration lung injury models.