Herbert et al reported association with obesity of a common DNA variant rs7566605 at 10 kb upstream of the INSIG2 gene. We analyzed rs7566605 polymorphism in 3125 Chinese in a cross-sectional study. We found no significant association of rs7566605 polymorphism with body mass index (BMI) and waist circumference among all participants (P=0.52). However, if geographic location is considered, the C/C genotype of rs7566605 was marginally associated with increased levels of BMI and risk of obesity among individuals living in Shanghai (P=0.06), indicating that the C/C genotype may contribute to obesity in certain subpopulation among Chinese under certain environmental settings.