〔Abstract〕 Objective To investigate the protective effect of resolvin D1(RvD1) on experimental colitis and its possible mechanism. Methods Mice were randomly divided into normal control group, RvD1 control group, model control group and RvD1 administration group. The colitis model was constructed by drinking 5% DSS solution freely and RvD1(50 μg/kg) was intraperitoneally injected into mice on 2 nd day, 4 th day and 6 th day. Disease activity index(DAI) score was measured during the experiment. At the end of the experiment, the peritoneal macrophages and the colon tissues were collected. Histological index(HI), myeloperoxidase(MPO), cytokine levels were measured and the structure of autophagosome in peritoneal macrophage was observed by electron microscope. The expression levels of related genes such as Beclin-1, p62, LC3-Ⅱ and pro-IL-1β were detected and analyzed by real-time PCR and Western blot. Results Compared with the model control group, the DAI score, HI score, MPO activity level and the level of proinflammatory cytokine decreased in the RvD1 administration group(P<0.05). The expression levels of Beclin-1, LAMP-2, LC3-Ⅱ/LC3-Ⅰ in peritoneal macrophages increased, and the expression levels of iNOS, IL-1β and p62 decreased(P<0.05). Conclusion RvD1 has a protective effect on experimental colitis, and the mechanism may be involved in the regulation of impaired autophagy in macrophages.