To explore the effect of Qingre Huashi Tiaoshu Recipe on mice with ulcerative colitis(UC) based on nuclear factor kappa B(NF-κB) signaling pathway and its mechanism.Methods:Six mice were randomly selected as the normal group from 36 SPF C57BL/6 mice.The remaining mice were given 2.5% dextran sulfate sodium(DSS) aqueous solution to establish a UC model.After evaluation of modeling，30 mice were randomly divided into a model group，a mesalazine group，and high，medium，and low-dose Qingre Huashi Tiaoshu Recipe groups.The latter three groups were given a daily dose of 3.38，1.69，and 0.845 g/(kg·d) of Qingre Huashi Tiaoshu Recipe suspension，respectively.The mesalazine group was given the daily dose of 0.52 g/(kg·d) mesalazine suspension，and the other two groups were given an equal volume of pure water.Each group was intervened continuously for 10 days.During intervention，the body weight of mice was measured.The disease activity index(DAI) after treatment was calculated.The colon length of mice was measured，and the histopathological changes in the distal colon obtained from mice were observed by hematoxylin-eosin(HE) staining.The expression levels of NF-κB p65 and p-NF-κB p65 in the colon was determined by Western blotting，and the value of p-NF-κB p65/NF-κB p65 was calculated.The mRNA levels of interleukin-1β(IL-1β)，interleukin-6(IL-6)，chemokine(KC/CXCL1)，and tumor necrosis factor-α(TNF-α) were detected by real-time quantitative polymerase chain reaction(RT-qPCR).Results:After intervention，as compared with the model group，the body weight of mice in the mesalazine group and the high and medium-dose Qingre Huashi Tiaoshu Recipe groups was increased significantly，the length of the colon partly recovered，and the pathological inflammation of colon tissue was alleviated.The difference of DAI before and after intervention was increased(P<0.05).The values of p-NF-κB p65 and p-NF-κB p65/NF-κB p65 and the mRNA levels of IL-1β，KC/CXCL1，IL-6，and TNF-α in the mesalazine group and the high and medium-dose Qingre Huashi Tiaoshu Recipe groups were decreased(P<0.05).Conclusion:Qingre Huashi Tiaoshu Recipe can attenuate the symptoms of mice with UC and ameliorate intestinal mucosal impairment.The mechanism may be related to the inhibition of the activation of the NF-κB pathway，thereby inhibiting inflammation.