Abstract: Objective To explore protective effect of taurine on the injury of hippocampus neurons induced by manganese.Methods Primary cultures of hippocapus neurons from new ly born Wistar rats were prepared.Cultured neurons were divided randomly into 8 groups of normal cultured,taurine,manganese treated(low,moderate,high),and taurine + manganese treated.The activity of lactate dehydrogenase (LDH) and apoptosis rates (a half quantitively and quantitively) were detected and the morphological changes of the neurons were observed.Results The activity of LDH in manganese treated groups increased significantly compared to normal cultured group(895.203 3±53.228 6 U/L) and that of taurine + low level manganese treated group(834.595 0±173.445 5) decreased significantly compared to low level manganese treated group (1 048.063±55.459 8).The apoptosis rates of moderate and high dose manganese treated groups were significantly higher than normal culture group and that of taurine + manganese treated group was significantly lower than manganese treated groups.The apoptosis and necrosis of the neurous in manganese treated groups wrere observed and those changes in taurine + manganese groupn were minor than in manganese treated groups.Conclusion Manganese could induce apoptosis of hippocampus neurons in dose-depended manner in vitro and taurine can antagonize the neurotoxicity of manganese at some extent.