The aim of this study was to investigate the effects of sanguinarine on alleviating the immune stress and inflammation induced by lipopolysaccharide (LPS) in the rice field eel (). The control (basal diet) and experimental groups (basal diet+750 μg/kg sanguinarine) were set, with 3 replicates in each group. After 8 weeks, 30 eels with consistent specifications were randomly selected from each repeat for the intraperitoneal injection of LPS. Samples were taken 0 h before injection and 3 h, 6 h, 12 h, 24 h, and 48 h after injection. The results showed that at 0 h, superoxide dismutase (SOD) activity in the liver of the experimental group was significantly higher than that of the control group, and there were no significant differences in the other indices. In the serum, glucose (GLU), cortisol (COR), immunoglobulin M (IgM), complement 4 (C4), alkaline phosphatase (AKP), glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), and SOD in the liver all showed a trend of first increasing and then decreasing after the injection of LPS, and reached a peak at 3 h or 6 h, while the malondialdehyde (MDA) in the liver showed the opposite trend. Compared with the control group, the contents of AKP, IgM, C4 in the serum, and SOD activity in the liver of the experimental group increased more after the LPS injection, while the contents of GLU and COR increased more slowly, and the GLU, COR, AKP, IgM, C4, GOT, and GPT recovered to normal levels more quickly. The expression levels of the genes in the intestinal tract first increased and then decreased after the injection of LPS, and reached a peak at 6 h or 12 h. Compared with the control group, the expression levels of were down-regulated in the experimental group, while the expression levels of were up-regulated. Taken together, the findings of the study indicate that under the conditions of this experiment, the injection of LPS induced immune stress and the inflammatory response in the rice field eel, which peaked at 3-6 hours. Furthermore, the addition of 750 μg/kg of sanguinarine into the feed could effectively relieve the immune stress and inflammatory response induced by LPS.