OBJECTIVE： To study the anti-inflammatory effect and its mechanism of the extract of Dcsmodium microphyllum， so as to provide experiment reference for further study of D. microphyllum. METHODS： Acute inflammatory model was established by xylene，glacial acetic acid and carrageenan. Using dexamethasone as positive control （0.005 g/kg）， inhibitory effects of intragastric different doses of the extract of D. microphyllum （50， 30， 15 g/kg） on xylene-induced ear swelling in normal mice and adrenalectomized mice， glacial acetic acid-induced permeability increasing of abdominal capillaries in normal mice， carrageenan-   induced paw swelling in normal mice and adrenalectomized mice were investigated. The levels of MDA， SOD and NO in the inflammatory tissue of toes of adrenalectomized mice were detected in carrageenan-induced inflammation model. Blank group was set for control （ig. equal volumn of water）. RESULTS： Compared with blank group， ear swelling degree of normal mice and adrenalectomized mice were decreased significantly in D. microphyllum extract high-dose and medium-dose groups while inhibitory rate of ear swelling was increased significantly； the permeability of abdominal capillaries of normal mice was significantly decreased in D. microphyllum extract groups； the swelling degree of toes in normal mice of D. microphyllum extract high-dose and middle-dose groups and adrenalectomized mice were significantly decreased while inhibitory rate of toe swelling was increased significantly （P＜0.05 or P＜0.01）. The levels of MDA and NO in the toe inflammatory site of adrenalectomized mice were decreased significantly in D. microphyllum extract high-dose and medium-dose groups， while the level of SOD was increased significantly （P＜0.05）. CONCLUSIONS： D. microphyllum extract can inhibit acute inflammation in mice significantly. Its anti-inflammatory mechanism is associated with decreasing MDA and NO while increasing SOD levels， and the anti-inflammatory effect does not depend on the hypothalamus-pituitary-adrenal axis system.