OBJECTIVE： To study improvement effects of Fuling gancao decoction on functional dyspepsia （FD） model rats. METHODS： Sixty SD rats were randomly divided into normal group， model group， Fuling gancao decoction high-dose group （20 g/kg）， Fuling gancao decoction low-dose group （10 g/kg）， drug combination group （Fuling gancao decoction 10 g/kg+domperidone 0.004 g/kg）， domperidone group （0.004 g/kg）， with 10 rats in each group. Except for normal group， other groups were givenicy dilute hydrochloric acid intragastrically to establish FD model.  After modeling， normal group and model group were given constant volume of distilled water at room temperature intragastrically， and other groups were given relevant drug solution （1 mL/100 g） intragastrically， once a day， for consecutive 7 d. The amount of gastric residue was measured to evaluate the gastric emptying function. Immunohistochemistry SP method was used to detect the protein expression of AQP3， Ghrelin and Substance P in gastric mucosa tissue. The protein expression of Claudin-1， Occludin and VIP were detected by Western blot assay. RESULTS： Compared with normal group， the amount of gastric residue was increased significantly in model group （P＜0.01）； positive expression of AQP3 and Ghrelin protein in gastric mucosa tissue was decreased significantly， while the positive expression of Substance P protein tended to increase； the protein expression levels of AQP3， Ghrelin， Claudin-1 and Occludin were decreased significantly， while those of Substance P and VIP were increased significantly （P＜0.05 or P＜0.01）. Compared with model group， the amount of gastric residue was decreased significantly in administration groups （P＜0.05 or P＜0.01）； the positive expression of AQP3 and Ghrelin protein tended to increase， while less positive expression of Substance P was found； the protein expression levels of AQP3 and Occludin in gastric mucosa tissue were increased significantly in administration groups， while those of VIP were decreased significantly  （P＜0.05 or P＜0.01）； the protein expression levels of Ghrelin and Claudin-1 in gastric mucosa tissue were increased significantly in Fuling gancao decoction high-dose group， Fuling gancao decoction low-dose group and drug combination group， while those of Substance P were decreased significantly （P＜0.05）. CONCLUSIONS： Fuling gancao decoction may improve the symptom of fluid retention in FD model rats by up-regulating the protein expression of AQP3， Ghrelin， Claudin-1 and Occludin and down-regulating the protein expression of Substance P and VIP in gastric mucosa tissue of rats.