Abstract: ObjectiveTo observe the effect of lead on the expressions of gene of NGF of hippocampi tissues of mature rats during the time of growth after birth.MethodsTo have the mother rat assimilate 0.2% of lead acetate after the birth of the young,the youngrat assimilate lead thr ough the milk.And adopt the method of RT-PCR to semi-quanititatively analyse the change of the content of NGF mRNA in the hippocampi tissues of the youngrat after the contact with lead during time of growth after birth.ResultsCompared with the control group.The content of lead in the lead-po lluted youngrat the hippocampi tissue went up,while the content of NGF mRNA in the hippocampi tissue went down.ConclusionThe pollution of lead may reduce the quantity of the show of NGF mRNA in the hippocampi tissues of youngrat when they were in the time of growth after the birth.