Abstract: Objective In order to understand the levels of environmental lead and the preschool children's body lead as well as the effects on children's physical development.Methods Lead contents of air,food and drinking water etc.were determined.Five hundred and one preschool children aged 3-6 years were detected for hair and blood lead levels and 264 of them were checked for physical development.Results It was estimated through calculation that each child in urban took in 54μg lead and in suburb 45μg every day.The hair lead levels of children in urban and in suburb were(18.71±8.8)μg/g and(13.97±8.0)μg/g,and blood lead levels were(131.2±72.1)μg/L and(108.3±68.1)μg/L and in suburb(1μg/L=0.004 83μmol/L),respectively.There were significant differneces between the children's hair and blood lead levels in urban and in suburb(P <0.001).The percentage of≥100μg/L of blood lead concentration in urban was 69.8% and in suburb was 40.1%.The physical development of the two groups of blood lead<100μg/L and≥100μg/L was compared in each age,and there were no significant differencs in height,weight,chest measurement,skull measurement and haemochrome content between the two groups.Conclusion The environmental lead pollution was serious in Chengdu area.The blood lead level and the prevalence of lead poisoning in preschool children were rather high.It was important to prevent the children's lead poisoning.