Lead is an neurotoxic substance and its clinical effect on the central nervous system has been well known since several decades ago. As the development of industry becomes more rapid and widespread in the world, we can expect the amount of lead and its harmful effect On the human life would increase in the future. We think the behavioural effect of lead on the central nervous system might be the result of the change of the neurotransmitters in the central nervous system. We studied the change of neurotransmitter amount in the cnetral nervous system of rats after lead intoxication. There was a significant neurotransmitter(catecholamine and 5 hydroxytryptamine) change after lead intoxication in our study.