Abstract: OBJECTIVE To research the influence of Yujin power on intestinal mucosal barrier in the rats model of antibiotic related large intestine dampness-heat syndrome. METHODS To establish the rats model of antibiotic related large intestine dampness-heat syndrome induced by internal and external factors. Sixty SD rats were randomly divided into the normal control group, the model group, positive control group (Sulfasalazine), high, middle and low dose of Yujin power groups, 10 rats in each group. The treatment lasted for 7 d. Body weights, food intake, anal temperature of all the rats were determined. Abdominal with drawal reflex and the parting grade of faeces shape were scored. The defecation frequency and stool water content were measured. The contents of TNF-α, IL-1β, DAO, D-lactate in serum, the SIgA content in colon mucosa and the MPO content in colon homogenates were assessed by radioimmunoassay. The number of Lactobacillus, Bifidobacterium, Enterococcus and Escherichia coli in the colon content of rats was measured and counted. The intestinal morphology was evaluated by histological examination. RESULTS Compared with the model group, after treatment with Yujin power for 7 d, all the indexes were recovered and high-dose of Yujin Power group performed the best and followed by middle-dose group. The rats body weight and food intake were increased, and anal temperature was decreased. The score of abdominal with drawal reflex and the parting grade of faeces shape were decreased, and the defecation frequency and stool water content were also decreased. The contents of TNF-α, IL-1β, DAO, D-lactate in serum, the MPO content in colon homogenates were decreased, but the SIgA content in colon mucosa was increased. The numbers of Lactobacillus, Bifidobacterium were increased, but the number of Enterococcus and Escherichia coli in the colon content of rats were decreased. Consequently, the HPS score was decreased as well. CONCLUSION Yujin power can reduce the intestinal mucosa injury in rats with antibiotic related large intestine dampness-heat syndrome. The mechanism can be related to inhibition against the excessive secretion of TNF-α, IL-1β, DAO, D-lactate in serum and the MPO content in colon homogenates or the less secretion SIgA content in colon mucosa, regulating intestinal flora to normal level.