Lead poisoning is one of the most significant environmental health threats which children face. The aim of the study was to evaluate the relationship between the blood lead level (BLL) of children and environmental pollution, as well as the effect of BLL on children's heath, in the biggest city in south-west China. A questionnaire survey was administered to 3,624 children's (6 months-7 years old) guardian in urban Chengdu from 2007 to 2009, collecting data on inhabited environment, living habits, and health status. All blood samples were collected for BLL test when the children came to the hospital. The analysis was conducted in West China Second University Hospital, Chengdu, China in December, 2009. A total of 3,624 children were included. The mean BLL was 62.31 μg/L. Three hundred thirty-three (9.2%) of 3,624 children's BLL were above 100 μg/L. Taking Chinese medicinal herbs usually, puffed foods, and substitutes of breast milk were risk factors (P < 0.05).The study shows that Chinese children's lead poisoning prevention and treatment lags far behind developed countries. The findings have implications for environmental health policy.