Over the a few decades, the incidences of obesity and associated metabolic syndrome diseases have been increased dramatically and resulted in a global health crisis. Recent findings suggest endocrine disrupting chemicals (EDCs) as an obesogen, because they disrupt normal development and homeostatic controls over adipogenesis and energy balance in obesity. Furthermore, risk of cardiovascular disease and mortality is elevated among those who were obese during childhood. Thus, we focused on etiology of obesity in children and performed biological monitoring of bisphenol A (BPA), which is a broadly exposed EDC in environment. Study subjects were age and sex-matched obese and normal children in Seoul (N=52; age, 8.67±1.46 years). Exposure levels of BPA were analyzed with HPLC/FLD as a conjugated form in urine. As results, ranges of urinary BPA were 0~54.38 ㎍/g creatinine (median, 4.57 ㎍/g creatinine). Levels of urinary BPA were 1.7 fold higher in the obese children than those in the controls (medians of obese and control children, 7.31 and 4.25 ㎍/g creatinine, respectively, p=0.22). In the near future, enlarge scaled studies should be performed to confirm the risk of BPA for obesity.