The SNP rs1746048 in CXCL12 associated with MI in our study, which is same with the result of Schunkert et al research but different from the result of another Chinese population reported by Lu et al [16], which the rs1746048 SNP had no relationship with CAD in Chinese population (OR = 1.01 P = 0.833). The gene discussed is CXCL12; the disease is myocardial infarction.