Objective: To explore the mechanism of Qingre Buyi Decoction (清热补益汤,QBD) in prevention and treatment of radiation enteritis in rats. Methods: Forty-eight Wistar rats were randomly divided into four groups, the TCM group, the WM group, the model group and the control group, 12 in each group. Rats in the former three groups were given orally with QBD, norfloxacin and normal saline once a day for 7 successive days, after being irradiated with X-ray at single dose of 10 Gy for modeling of radiation enteritis, while rats in the control group were untreated. Animals were sacrificed at the end of the medication. NO concentration, mean height and number of villi per centimeter in their small intestinal mu-cosa were measured. Results: The intestinal NO concentration was significantly lower in the TCM and WM groups than that in the model group(P<0.05), while the number of villi was significantly more and the height higher in the former two groups than those in the model group (P<0.01 for both), but no signif Objective: To explore the mechanism of Qingre Buyi Decoction (Qing Decoction, QBD) in prevention and treatment of radiation enteritis in rats. Methods: Forty-eight Wistar rats were randomly divided into four groups, the TCM group, the WM group, the Model group and the control group, 12 in each group. Rats in the former three groups were given orally with QBD, norfloxacin and normal saline once a day for 7 After days, after being irradiated with X-ray at single dose of 10 Gy for Model of radiation enteritis, while rats in the control group were untreated. Animals were sacrificed at the end of the medication. NO concentration, mean height and number of villi per centimeter in their small intestinal mu-cosa were measured. Results: The intestinal NO The concentration was significantly lower in the TCM and WM groups than that in the model group (P<0.05), while the number of villi was significantly more and the height higher in the former two groups than those in the model group (P<0.01 f Or both), but no signif