Objective:To study the anti-inflammatory effects of low， middle， and high doses of Anchang decoction on ulcerative colitis in SD rats， and also explore the possible mechanism of Anchang decoction in the prevention and treatment of ulcerative colitis through the effect of different doses on miRNA-146a/non-receptor tyrosine protein kinase（JAK）/signal transduction and activator of transcription 3（STAT3）/cytokine signaling protein-3（SOCS-3） signal pathway and its downstream proteins. Method:The experimental rats were divided into control group ， model group ， mesalazine group（1 g·kg^-1） and Anchang decoction low（6 g·kg^-1）， middle（12 g·kg^-1）and high dose groups（24 g·kg^-1）， with 10 rats in each group. Except for the control group， 2，4，6-trinitrobenzenesulfonic acid （TNBS）/ethanol enema was used in all the other groups to establish a rat model of ulcerative colitis for 14 days respectively. The general changes of the mental state， stool traits， hair and other general conditions of the rats were observed， and score was graded with reference to the disease activity index （DAI） table. The pathological changes of colon tissue of rats in each group were observed by hematoxylin-eosin （HE） staining. The levels of serum tumor necrosis factor-α（TNF-α）， interleukin-10（IL-10）， interleukin-17（IL-17）， interleukin-1β（IL-1β）and interleukin-6（IL-6）were detected by enzyme linked immunosorbent assay （ELISA）. The expression levels of JAK2， phosphorylation STAT3 （p-STAT3）， STAT3 and inhibitor of SOCS-3 in colon tissue were detected by Western blot. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the expression of JAK2， p-STAT3， STAT3， SOCS-3 mRNA in rat colon and miRNA-146a in rat plasma. Result:Compared with the normal group， the expression of JAK2， p-STAT3， STAT3 protein and the expression of JAK2， p-STAT3 and STAT3 mRNA in the model group increased （P<0.05）， and the relative expression of miRNA-146a， SOCS-3 mRNA and SOCS-3 protein decreased in the model group （P<0.05）. Compared with the model group， the mental state， food intake， coat color， etc. of rats in the administration groups were significantly improved， the DAI score was significantly reduced （P<0.05）， the colonic ulcer tissues of rats in the administration groups were improved significantly， the expression levels of JAK2， p-STAT3， STAT3 protein and the expression of JAK2， p-STAT3 and STAT3 mRNA in the colon tissue of the administration groups were decreased （P<0.05）， and the relative expression levels of miRNA-146a， SOCS-3 mRNA and SOCS-3 protein were increased in the administration groups （P<0.05）. Conclusion:Anchang decoction can alleviate ulcerative colitis and reduce the activation of inflammatory factors by affecting the expression of genes and proteins related to miRNA-146a/JAK/STAT/SOCS-3 signal transduction pathway.