The effects of Wumeiwan (WMW) on TNF-α, IL-6, IL-8, IL-10 and NF-κBp65 in rats with ulcerative colitis (UC) were investigated, the curative effectiveness of WMW vs salicylazosul-fapyridine (SASP) was compared, and the action mechanism was analyzed. Fifty-Six Spra-gue-Dawley (SD) rats were randomly divided into four groups (n=14 in each group, with equal ratio of male and female): normal control group, model group, SASP group, and WMW group. Except normal control group, the rat UC models in the remaining three groups were established using the method of 2.4-dinitrochlorobenzene (DNCB) immunization and acetic acid local enema. The rats in model group, SASP group, and WMW group were treated with distilled water, SASP, and WMW re-spectively. The changes in the symptoms and signs were observed, and levels of IL-6, IL-8, TNF-α,IL-10 and the expression of NF-κBp65 in the colonic tissues were statistically analyzed. The results showed that the levels of IL-6, IL-8, and TNF-α were significantly increased (P<0.01), while those of IL-10 significantly reduced (P<0.01) after establishment of rat UC models as compared with normal control group. The levels of IL-6, IL-8, and TNF-α were obviously lower, bat the level of IL-10 was obviously higher in WMW and SASP groups than those in model group (P<0.05). The levels of IL-6,IL-8, and TNF-α were lower, while the level of IL-10 was higher in WMW group than in SASP group.NF-κBp65 was expressed negatively or weakly in normal colonic tissues. The positive expression rate of NF-κBp65 in WMW group and SASP group was obviously lower than in model group (P<0.01), and there was significant difference between WMW group and SASP group (P<0.05). It was concluded that rat UC model was established successfully. WMW could up-regulate the expres-sion oflL-10, down-regulate the expression ofTNF-α, IL-6, IL-8, and inhibit the NF-κBp65 activity to adjust immune function, indicating WMW had better curative effects on UC in rats.