Objective：To investigate the association of a common functional polymorphism （Asp327Asn） in the sex hormone-binding globulin（SHBG）gene with type 2 diabetes mellitus （T2DM） in Chinese Han population. Methods：Asp327Asn polymorphism in 248 cases（T2DM group） and 351 controls （NC group） were genotyped by polymerase chain reaction-restriction fragment length polymor－phism （PCR-RFLP） technique.Homeostatic model assessment （HOMA） was used to assess beta cell function（HOMA-B） and in－sulin resistance （HOMA-IR）. Results：The variant Asn allele frequency was significantly lower in T2DM group than（14.5％，20.1％，respectively） that in NC group.Unconditional logistic regression analysis showed that the variant Asn allele was associated with a re－duced risk of T2DM（OR=0.62，95％CI:0.42~0.91，P=0.016）． Conclusion：This study suggests that the Asn allele in the SHBG gene might be related to a reduced risk of T2DM in the Chinese Han population.