Abstract: Objective To investigate changes of neurobehavioral function in electrolyzing-aluminum workers exposed to both aluminum and fluoride and to study the exposure-effect relationship,and to explore the toxic mechanism.Methods Neurobehavioral Core Test Battery(NCTB)recommended by WHO was used for 65 electrolyzing-aluminum workers and 52 healthy workers.Meanwhile,following items were determined correctly:plasma aluminum and fluoride concentration,plasma glutathione peroxidase(GSH-Px)activity,plasma malonyl dialdehyde(MDA) content,whole blood superoxide dismutase(SOD)activity,and choline esterase activity.Results Compared with the control group,the exposed group had plasma aluminum and fluoride concentration increased,GSH-Px activity reduced,MDA content increased and SOD activity increased,and choline esterase activity reduced significantly(P<0.001) There was significant difference of NCTB scores among groups in most items Plasma fluoride concentration correlated with scores of digitspan、Santa Ana and Pwrofile of Mood States.Conclusion Occupational exposure might interfere with neurobehavioral function of electrolyzing-aluminum workers The exposure-effect relationship between plasma fluoride concentration and NCTB scores might exist In neural toxicity,fluoride was maybe the main occupational hazard factor The mechanism perhaps was:changes of neurobehavioral function was induced because the lipid peroxidation reaction was intensified and choline esterase activity was inhabited by fluoride