Objective: To study the anti-fatigue action of different extracts from Portulaca oleracea in senile mice by D-gal

and its mechanisms. Method: The mice were randomly divided into 4 groups:control group

model group

the n-butanol extracts from P. oleracea(0.5

0.25 g·kg-1) groups and the ethanol extracts from P. oleracea(1

0.5 g·kg-1) groups. The control group is given hypodermic injection of isotonic NaCl in the transverse part while the other groups successively administered by hypodermic injection of D-gal(1 g·kg-1). It is made a model of senile mice after 42 d continuation. To measure anti-fatigue performances with the Fatigue Instrument. To measure malondialdehyde(MDA) contents and superoxide dismutase(SOD) activity in brain tissue of senile mice. Result: The n-butanol extract from P. oleracea (0.5 g·kg-1) and the ethanol extract from P. oleracea(1 g·kg-1) could improve anti-fatigue performances.The n-butanol extracts from P. oleracea(0.5

0.25 g·kg-1) could decrease MDA contents and SOD activity in brain tissue. The ethanol extract from P. oleracea (1 g·kg-1) could decrease MDA contents n brain tissue. Conclusion: The n-butanol extract from P. oleracea and the ethanol extract from P. oleracea can improve anti-fatigue performances. Its mechanism maybe related by improve SOD activity and decrease MDA contents. The n-butanol extract from P. oleracea is better than the ethanol extract from P. oleracea.