Uncoupling protein-1 (UCP-1) plays a major role in thermogenesis, and has been implicated in the pathogenesis of obesity and metabolic disorders. The aim of this study was to estimate the effects of A-3826G polymorphism of UCP-1 gene on body fat distribution. Two hundred forty eight Korean female overweight subjects with BMI more than 25 kgfm2 participated in this study. The areas of abdominal subcutaneous and visceral fat of all subjects were measured from computed tomography cross sectional pictures of the umbilical region. Subcutaneous fat areas of upper and lower thigh were also measured. Body composition was measured by bio-impedance analysis, and serum concentrations of biochemical parameters, such as glucose, triglyceride, cholesterol etc, were also measured. Genotype of UCP-1 was analyzed by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method. The frequencies of UCP-1 genotypes were AA type; $27.8\%,;AG;type;;51.2\%;and;GG;type;;21.0\%,$ and the frequency of G allele was 0.47. Body weight, BMI, WHR, SBP, DBP and body compositions were not significantly different by UCP-1 genotype. Abdominal visceral fat area was significantly higher in AG and GG type compared with AA type (p=0.009), but subcutaneous fat areas were not significantly different by UCP-1 genotype. Among biochemical parameters, LDL cholesterol level was significantly higher in GG type compared with AA and AG types (p=0.033). Among all subjects, 121 subjects finished 1 month weight loss program containing hypocaloric diet and exercise. The reduction of body weight and BMI were lower in GG type compared with AA/AG type even though statistical significances were not found (p > 0.05). These results suggest that UCP-1 genotype has a significant effect on visceral fat accumulation among Korean female overweight subjects with BMI more than $25;kg/m^2$