OBJECTIVE： To observe the effects of asiaticoside on peroxisome proliferator activated receptor gamma （PPAR-γ） protein expression in hippocampal tissue of Alzheimer disease （AD） model rats. METHODS： SD rats were randomly divided into sham operation group， model group， positive control group （Donepezil tablets，1 mg/kg） and asiaticoside low-dose， medium-dose and high-dose groups （5， 15， 45 mg/kg）， with 10 rats in each group. Except for sham operation group， those groups were given intracerebral injection of Aβ1-42 to induce AD model. Sham operation group and model group were given constant volume of normal saline intragastricaly， and treatment groups were given relevant medicine intragastrically， once a day， for consecutive 2 weeks. Spatial memory ability of rats was detected by Morris water maze test； Aβ1-42 deposition in hippocampus tissue was detected by immunohistochemical method； the expressions of IL-6 and TNF-α in hippocampus tissue were detected by ELISA； the protein expression of PPAR-γ in hippocampus tissue was detected by Western blot assay. RESULTS： Compared with sham operation group， spatial memory ability of rats was retarded in model group， manifesting as average incubation period was prolonged and the times of crossing original platform decreased （P＜0.05 or P＜0.01）； the expression of IL-6 and TNF-α in hippocampus tissue were increased while that of PPAR-γ was decreased， and Aβ1-42 deposition was greatly increased （P＜0.01）. Compared with model group， spatial memory ability of rats was improved in treatment groups， manifesting as average incubation period was shortened and the times of crossing original platform increased （P＜0.05 or P＜0.01）； the expression of IL-6 and TNF-α in hippocampus tissue were decreased， while that of PPAR-γ was increased， and Aβ1-42 deposition was decreased （P＜0.01）. CONCLUSIONS： Asiaticoside can improve spatial memory ability of AD model rats by improving the expression of PPAR-γ in hippocampus tissue and inhibiting the expression of IL-6 and TNF-α.