OBJECTIVE: To investigate the effect on allieving diarrhea and immual system in treatment of diarrhea due to hypofunction of the spleen in rat model, and reveal the mechanism between declination of immunologic function and diarrhea.  METHODS: The QWBZS has been applied to diarrhea of rat model sufferred from spleen deficiency after taking Rhubarb. The variation of index in rats has been observed ,such as: ingestion spontaneous activity, spleen/thymus gland weight, RBC-C_3b-RR, RBC-IC-R and the rate of carbon powder propused, the phagocytosis of macrophage, the content of serum amylase and D-xylose.  RESULTS: 1.compared with the blank, the model is P0.05  CONCLUSIONS: 1.The QWBZS could improve motor function and absorptive function on intestine of the spleen hypofunction in rat model.  2. The QWBZS could strengthen the immunologic function of the spleen hypofunction in rat model.