Abstract: Objective To research the relation between blood alcohol concentration(BAC) and neurobehavioral function after drinking.Methods The neurobehavioral ability index(NAI) of 233 volunteers were measured with computer-administered neurobehavioral evaluation system-Chinese3(NES-C3).Results The NAI of simple visual reaction time and mental arithmetic declined when BAC was more than 0.157 mg/mL,the NAI of benton visual retention,length discrimination and digit cancel declined significantly when BAC was more than 0.204 mg/mL.Conclusion The neurobehavioral function declined significantly when BAC increased and recovered gradually when BAC declined due to the elimination of alcohol in blood.

Key words: forensic toxicology, neurobehavioral manifestations, neurobehavioral ability index, blood alcohol concentration