OBJECTIVE: To investigate blood lead levels (BLLs) and influencing factors of BLLs among preschool children living in towns of Hunan Province. METHODS: A total of 2 044 preschool children (1 108 boys and 936 girls) from towns of 12 regions in Hunan Province were enrolled by a cluster sampling between September 2008 and June 2009. The average age of the children was 4.4±1.1 years (range 2 to 6 years). BLLs were determined using the atomic absorption spectrographic method. The influencing factors of BLLs were investigated using a standard questionnaire and logistic regression analysis. RESULTS: The mean BLLs of the children were 81.9±34.5 μg/L. BLLs more than 100 μg/ L were noted in 482 children (23.58%). Of the 482 children, 472 (23.09%) showed BLLs of 100-199 μg/L and 10 (0.49%) showed BLLs ≥200 μg/L. There were significant differences in the prevalence of elevated BLLs (≥100 μg/L) among different age groups (P<0.01). The prevalence of elevated BLLs in boys (28.99%) was significantly higher than that in girls (21.98%) (P<0.01). There were significant differences in the prevalence of elevated BLLs in children from different regions (P<0.01). The logistic regression analysis showed that the male(OR=1.449, P<0.01), father’s occupational lead exposure (OR=1.314, P<0.01)and maternal frequent use of hair dyes (OR=1.678, P<0.05) were risk factor for elevated BLLs. CONCLUSIONS: The prevalence of elevated BLLs is higher in preschool children living in towns of Hunan Province and is associated with a child’s region and age. The male, father’s occupational lead exposure and maternal frequent use of hair dyes are risk factor for elevated BLLs. ［Chin J Contemp Pediatr, 2010, 12 (8):645-649］