To identify markers contributing to the genetic susceptibility to heroin dependence, this study examined the potential association between heroin dependence and 15 single nucleotide polymorphisms (SNPs, rs1978340, rs3762556, rs3791878, rs3749034, rs11542313, rs2241165, rs2241164, rs769407, rs3749033, rs16858977, rs701492, rs16858988, rs4668331, rs7578661, rs769395) of GAD1 gene using the MassARRAY system.