Obesity is a clinical syndrome which is driven by interactions between multiple genetic and environmental factors. Monogenic obesity is a rare type of obesity which is caused by a mutation in a single gene. Patients with monogenic obesity may develop early onset of obesity and severe metabolic abnormalities. In this study, we screened mutations of LEP in a total of 135 Chinese individuals including 35 obese patients whose BMI ≥ 32 kg/m(2) and 100 controls with BMI < 25 kg/m(2). Moreover, detailed information and clinical measurements of the participants were also collected. Finally, we identified a novel nonsynonymous mutation H118L in exon 3 of LEP in one patient with BMI 46.0 kg/m(2). This mutation was not identified in the controls. We speculated that the mutation H118L in LEP might be associated with severe obesity in Chinese subjects. However, the substantial mechanism should be further investigated.