Abstract: Objective: To observe the therapeutic effect of Linggui Zhugan Tang and Tingli Dazao Xiefei Tang retention enema on rats with formaldehyde induced acute pulmonary edema. Methods:40 adult SPF rats were randomly divided into blank control group(NC), formaldehyde model control group(F- MC), traditional Chinese medicine low- dose enema treatment group(CM-L) and traditional Chinese medicine high-dose enema treatment group(CM-H), with 10 rats in each group. Rats in F-MC, CM-L and CM-H groups inhaled 94.4 mg/m3 formaldehyde for 2 hours to establish the model of acute pulmonary edema. In NC group,ddH2O(Double steaming water) was used instead of formaldehyde.Rectal retention enema was given immediately. In CM- L and CM- H groups , Linggui Zhugan Tang and Tingli Dazao Xiefei Tang were used , with doses of 1.0 mL/100 g and 1.5 mL/100 g respectively. NC and F-MC groups were treated with 0.9% sodium chloride 1.0 mL/100 g. The maximum enema volume of each group was calculated by body mass. Urine volume was observed and measured within 5 hours after enema. After 5 hours, serum superoxide dismutase(SOD), malondialdehyde(MDA), total antioxidant capacity of plasma and red blood cells(T-AOC),lung wet weight,lung/system number and lung/heart coefficient were measured. Pathological sections of lung tissues were taken for observation. Results: Compared with F- MC group, lung wet weight, lung/system number and lung/heart coefficient in CM- L and CM- H groups decreased significantly(P< 0.05,P<0.01),urine volume increased significantly(P<0.01),plasma T-AOC decreased significantly,erythrocyte T-AOC increased significantly,serum SOD increased significantly and MDA decreased significantly(P<0.05,P<0.01). The changes of various indexes in CM-H group were more obvious than those in CM-L group(P<0.05). Pathological sections showed that the alveolar wall of lung tissue in F-MC group was dilated and congested,and a large amount of edema fluid was seen in the alveolar cavity, which was diffusely distributed. In CM- L and CM- H groups, some alveolar walls were dilated and congested,and edema fluid was seen in the alveolar cavity,which was distributed in small foci. Conclusion:The retention enema of Linggui Zhugan Tang and Tingli Dazao Xiefei Tang has obvious curative effect on formaldehyde induced acute pulmonary edema in rats,which may be related to relieving pulmonary pressure,inhibiting and reducing the formation and exudation of inflammatory mediators, reducing inflammatory reaction, tissue injury, improving antioxidant effect and improving immune ability.