Abstract: Objective To explore the effect of lead on learning,memory and the expression of IL-1βmRNA and protein in rats for the study of neurotoxic mechanism of lead.Methods Pregnant mice(10 for each group)were exposed to low(0.3 g/L),moderate(1.0 g/L),and high-level(3.0 g/L)of lead acetate in deionized drinking water from the first day of gestation to 21th postnatal day(PND).The lead concentration in blood and hippocampus were determined at 7th,14th, 21th day of neonatal mice pups.The ability of learning and memory and the expression of IL-1βmRNA and protein in hippocampus of different groups at 21th day were measured.Results The lead concentration in lead exposure group was higher than that of in control group(P<0.05).In water Morris maze test,there was statistical significance in moderate and high lead exposure group(P<0.05).The relative expression level of IL-1βmRNA in control group,low,moderate,high lead exposure group were 0.073±0.016,0.572±0.287,1.090±0.521,and 1.312±0.837 and the expression of IL-1β protein was 0.708±2.260,8.958±2.257,19.375±1.644,and 25.125±4.748,respectively.The expressions of IL-1β mRNA and protein were higher in lead exposed groups than that of in the control group(P<0.05).Conclusion Lead may affect learning and memory and cause nervous system damage by inducing IL-1β expression in hippocampus in mice.