Objective To study the effects of exposure to low level lead on neurobehaviors of preschool children. Methods Blood lead levels were measured in 211 preschool children aged 4-6 years in a kindergarten without known exposure to lead sources; the 211 children were assigned into two groups: low blood lead level group (LL group, <100 μg/L ) and high blood lead level group (HL group, ≥100 μg/L). Their neurobehaviors were assessed with Achenbach child behavior checklist (CBCL) to study the relationship between blood lead and CBCL total behavior scores (TBPs), internalizing and externalizing scores (Ints and Exts). Results The Exts and incidence of abnormal behavior problems in the HL group ( 13.28 ± 6.26 and 18.26% , respectively) were much higher than those in the LL group ( 9.98 ± 5.46 and 7.29% , respectively)(t= 4.0677 , χ 2= 5.470 , P< 0.05 ). The blood lead level was positively correlated significantly with the scores for hyperactivity, attack and disobedience (r= 0.3164 , 0.2828 , 0.1886 , P< 0.05 ). When the blood lead levels of children reached or exceeded 150 μg/L, the incidence of abnormal behavior problems increased significantly. Conclusions Low level lead exposure can have adverse effects on neurobehaviors of preschool children. Objective To study the effects of exposure to low level lead on neurobehaviors of preschool children. Methods Blood lead levels were measured in 211 preschool children aged 4-6 years in a kindergarten without known exposure to lead sources; the 211 children were assigned into two groups : Low blood lead level group (LL group, <100 μg / L) and high blood lead level group (HL group, ≥ 100 μg / L). Their neurobehaviors were assigned with Achenbach child behavior checklist (CBCL) to study the relationship between Results The Exts and incidence of abnormal behavior problems in the HL group (13.28 ± 6.26 and 18.26%, respectively) were much higher than those in the LL group (9.98 ± 5.46 and 7.29%, respectively) (t = 4.0677, χ 2 = 5.470, P <0.05). The blood lead level was positively correlated with the scores for hyperactivity, attack and disobedience (r = 0.3164, 0.2828, 0.1886, P <0.05). When the blood lead levels of children reached or exceeded 150 μg / L, the incidence of abnormal behavior problems significantly significantly. Conclusions Low level lead exposure can have adverse effects on neurobehaviors of preschool children.