BACKGROUND: Body mass index(BMI)is a commonly used phenotype for obesity,which is determined by multiple genetic factors.OBJECTIVE: To investigate whether osteocalcin(also known as bone Gla protein,BGP)Hind Ⅲ genetic polymorphism is associated with BMI variation.METHODS: A total of 390 premenopausal women from a local population of Nanchang City were selected.Body weight and height were measured.All participants were genotyped at the BGP Hind Ⅲ locus using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).RESULTS AND CONCLUSION: The BGP genotype frequencies of HH,Hh and hh were 0.077,0.408 and 0.515,respectively.The distribution of BGP Hind Ⅲ genotypes was consistent with Hardy-Weinberg equilibrium(P > 0.05).The BGP Hind Ⅲ were significantly associated with BMI(P=0.002),which could explain about 5.47% of BMI variation.On average,BMI of individuals with HH genotype was the highest[(22.81±0.73)kg/m2],individuals with Hh genotype was intermediate[(21.50±0.53)kg/m2],while individuals with hh genotype was the lowest[(20.23±0.63)kg/m2].Therefore,carriers of HH and Hh genotypes had,respectively,approximately 12.75% and 6.28% higher BMI than carriers of the hh genotype.To our best knowledge,this is the first study reporting the association of BGP Hind Ⅲ genetic polymorphism and BMI in healthy premenopausal women.