Objective:To investigate the effects of CCK-8 receptor on lung injury in endotoxemia rats. Methods: Male SD rats were randomized into four groups (n=6): control group (LPS+CCK-8 group), CCK-1R antagonist group, CCK-2R antagonist group, DFSO+PF group. The rats were injected by LPS (5 mg.kg-1). CCK-8 (20 μg.kg-1) was administered 30 min after LPS injection. Either a specific CCK-1R antagonist or CCK-2R antagonist (0.5.kg-1) was injected before CCK-8 treatment (after LPS 20min). The tidal volume (TV) was collected by a multi-channel data physiological recorder. The lung injury was observed by light and electron microscopy. The concentrations of TNF-α、IL-1 and IL-6 in lung homogenates were measured by ELISA kits.Rresults: Compared with control group, the TV were significantly lower and the lung injuries were more serious in CCK-2R antagonist group. As well as the concentrations of TNF-α、IL-1 and IL-6 in lung homogenates were higher.Conclusion: CCK-2 receptor plays a major role in the effect of CCK-8 on lung injury in ETM rats.