Abstract: Objective:To investigate Ethyl acetate extract of Centella asiatica on the abilities of learning and memory and contents of APP,BACE1 m RNA in SAMP8 with Alzheimer'disease. Methods:SAMP8 were randomly divided into 5 groups:the model control group,Ethyl acetate extract of Centella asiatica high-dose(40 g·kg-1),middose(20 g·kg-1),low-dose(10 g·kg-1) group and huperzin A group(0.386 m g·kg-1). Each mouse was administered intragastricly for 2 months. The same amount of double distilled water was given to the model control group. The test of Morris water maze(MWM) was used to examine the changes of the abilities of learning and memory. The contents of APP and BACE1 m RNA in brain tissue were assayed by reverse transcription polymerase chain reaction(RT-PCR). Results:Morris water maze demonstrated that mice treated with Ethyl acetate extract of Centella asiatica and huperzine A,mean escape latencies were significantly decreased( p < 0. 01), the residence times were significantly prolonged( p < 0. 01), the percentages of total swimming distance in the platform quadrant were significantly increased(p<0.01,p<0.05) and seek times in mid-dose group of the ethyl acetate extract of Centella asiatica and huperzine A group were more than that of the model control group(p<0.01). The result of RT-PCR showed that high,mid-dose groups of the ethylacetate extract of Centella asiatica and huperzine A group could reduce the contents of APP and BACE1 m RNA. Conclusion:Ethyl acetate extract of Centella asiatica had a significant relieving effect on the lesion of the abilities of learning and memory,it could reduce the contents of APP and BACE1 m RNA in SAMP8.