to investigate into the effect of Rejuvenation Decoction on ultramicrostructure of cortical neuron of ageing mice induced by D-galactose. Method:mice studied were randomly divided into blank group, model group of ageing, Vitamin E group, low dose group of Rejuvenation Decoction, high dose group of Rejuvenation. After intragastrically administered for six weeks, we studied the ultramicrostructure of cortical neuron in mice. Result:high dose group of the decoction had advantage over the VE group for improvement of the ultramicrostructure of cortical neuron in mice. Other parameters showed no significant difference with VE group(P<0.05). Conclusion:Rejuvenation Decoction help delay the ageing process of mice’ brain.