Abstract: Objective To learn nerve-system toxicity of REs and pro vide information for new normal daily allowance intake,the effect of long-termintake of Y³⁺ at different dose on anti-oxidative system and monoamine neuro transmitter of rats' brain were observed.Methods The ablactation rats and their F1 generation were fed with water dissolved Y³⁺ at different level(0,53.4,5 340 mg/L).After 6 months,contents of DA(dopamine),N E(norepinephrine),5-HT(5-hydroxytryptamine),5-HIAA(hydroxyindole acetic acid),ROS(reactive oxygen species)and MDA(malondialdehyde),and activities of MAO(monoamine oxidase),SOD(superox ide dismutase)and CAT(catalase)in F1 rats were detected.Results No significant changes in DA,NE,5-HIAA,5-HT,MDA and the activities of SOD,CAT,ROS were observed for the low dose group,in contrast with remar kably decreases in the concentration of 5-HT and 5-HIAA and remarkably increases in the activities of ROS,MAO and MDA.Conclusion Y³⁺ in 5340 mg/L could induce the oxidative damage and decrease in monoamine neurotransmitter,which might be responsible for the loss in learning and memory in rats.