Abstract: Objective To study the effect of losartan on expression of lectin-like oxidized LDL receptor-1 (LOX-1) protein in acute lung injury (ALI), to investigate its role in the process and mechanism of the effect of losartan on ALI. Methods Rats were randomly divided into normal control group, lipopolysaccharide (LPS) group (5mg/kg), and LPS+Losartan group, each group 10 rats. Rats in LPS+Losartan group were given an intraperitoneal injection of losartann (8mg/kg) after LPS administration. The level of PaO2, wet/dry ratio(W/D), the concentration of protein and TNF-α in bronchoalveolar lavage fluid (BALF), T?N?F-α concentration in plasma, lung MPO (myeloperoxidase) activity by chromometry and lung tissue histopathological changes were examined, LOX-1 mRNA was detected by RT-PCR analysis, the expression of LOX-1, ICAM-1, Cleaved caspase-3 protein in lung was measured by Western blot. Results Histological examination showed that extensive lung inflammation were seen in the LPS group. The level of PaO2 in LPS group decreased compared with taht in sham group (P<0.05). The level of W/D , concentration of protein in BALF, TNF-α in BALF and plasma, lung MPO activity, the expression of LOX-1 mRNA, LOX-1, ICAM-1 and Cleaved caspase-3 protein in LPS group were increased significantly respectively compared with those in sham group (P<0.05). Compared with LPS group these changes were markedly attenuated in LPS+Losartan group (P<0.05). Conclusion There is protective effect of losartan on ALI, which may result from inhibiting the inflammation and apoptosis induced by LOX-1.