OBJECTIVE： To compare the pharmacodynamics of active parts in crude Atractylodes lancea and A. lancea fired with bran. METHODS： 170 rats were randomly divided into 17 groups， including blank control group， spleen and stomach damp obstruction model group， volatile oil of crude A. lancea and A. lancea fired with bran high-dose and low-dose （0.747， 0.083 mg/ml by the concentration of crude medicinal materials， similarly hereinafter） groups， solvent control 2％ polysorbate 80 group， dichloromethane extract of crude A. lancea and A. lancea fired with bran high-dose and low-dose groups， solvent control 1‰ polysorbate 80 group， n-butyl alcohol extract of crude A. lancea and A. lancea fired with bran high-dose and low-dose groups， solvent control stomach damp obstruction model distilled water control group. Except blank control group， other 16 groups were given Sennae folium decoction ig for 14 d to induce spleen and stomach damp obstruction model， and then received relevant medicine or solvent ig once a day for consecutive 7 d. Body weight of rats were determined before and after medication， and the serum levels of amylase， D-xylose， gastrin， vasoactive intestinal peptide and NO were determined after medication. RESULTS： Compared with spleen and stomach damp obstruction model group， the body weight and serum levels of gastrin， amylase and D-xylose increased significantly in rats of active part in A. lancea fired with bran groups （P＜0.05）， while vasoactive intestinal peptide and NO decreased significantly （P＜0.05）. Compared active part in crude A. lancea group， except the body weight， above indicators of active part in A. lancea fired with bran groups had greater change， with statistical significance （P＜0.05）. CONCLUSIONS： There are pharmacodynamic differences in the active parts between crude A. lancea and A. lancea fired with bran， the latter one is stronger.