OBJECTIVE: To study the mechanism of Aurantii fructus immaturus (AFI) and its main active ingredients in promoting gastrointestinal motility of model rats with spleen deficiency. METHODS: 170 rats were randomly divided into blank group (10 rats) and modeling group (160 rats), rats in modeling group was induced models with spleen deficiency by bitter cold diarrhea+irregular diet. After modeling, rats were randomly divided into model group, naringin (NA) low-dose, medium-lose, high-dose groups (3.267, 6.535, 13.070 mg/mL), neohesperidin (NE) low-dose, medium-lose, high-dose groups (3.865, 7.730, 15.460 mg/mL), synephrine (SY) low-dose, medium-lose, high-dose groups (0.252, 0.504, 1.008 mg/mL), compatibility groups with 3 monomer ingredients (NA-NE-SY) low-dose, medium-lose, high-dose and AFI water decoction low-dose, medium-lose, high-dose groups (0.104, 0.208, 0.416 g/mL, calculated by crude drug), ig, once a day, 10 mL/kg, for 7 d. After the last administration, gastrin (GAS) in serum, and acetylcholine (ACh), motilin (MTL), substance P (SP), vasoactive intestinal peptide (VIP) levels in plasma were detected. RESULTS: Compared with blank group, GAS level in serum and ACh, MTL, SP levels in plasma in model group were reduced (P<0.01), VIP level in plasma was increased (P<0.05). Compared with model group, except for the GAS level in serum showed no obvious change in NA high-dose group and SY doses groups, other medicine groups were obviously increased (P<0.05 or P<0.01); the ACh levels in serum were obviouly increased in NE high-dose group, SY high-dose group and AFI water decoction low-dose group (P<0.01). MTL levels in plasma were obviously increased in NE medium-dose, high-dose groups, SY high-dose group, compatibility low-dose, medium-dose groups and AFI water decoction medium-dose, high-lose groups (P<0.05); SP levels in plasma were obviously increased in NA low-dose, medium-dose groups and NE doses groups (P<0.05 or P<0.01); VIP levels were reduced in NA low-dose group, SY high-dose group and AFI water decoction low-dose, medium-lose groups (P<0.05). CONCLUSIONS: AFI may promote the gastrointestinal motility of model rats with spleen deficiency by promoting the secretion of GAS, ACh, MTL, and inhibiting the secretion of VIP; there are differences between AFI and the 3 monomer ingredients in regulation of gastrointestinal hormones.