Objective：To explore the relationship between toll-like receptor 9 （TLR9） gene and cardiovascular disease by bioinformatics analysis of TLR9 gene and its -1237t / C polymorphism. Methods：The physical and chemical properties，single nucleotide polymorphism（SNP） sites，associated gene interaction and GO function annotation of TLR9 were analyzed by bioinformatics.The genomic DNA of peripheral blood was extracted from 189 plasma samples （including 68 patients with cardiovascular disease and 121 healthy controls）. After gene amplification，the amplified products were digested，typed and sequenced，the correlation with cardiovascular disease was statistically calculated. Results：TLR9 is a hydrophilic basic protein with four nuclear localization signals and several potential linear B cell epitopes. The secondary structure of the protein is mainly α helix. As a hub protein，TLR9 interacts with 10 proteins such as MYD88，TBK1 and CD40，and is mainly enriched in Toll-like receptor signal pathway and inflammatory response signal pathway. The distribution frequencies of TT and TC genotypes were 71.90% and 28.10% in the healthy control group，47.06% and 52.94% in the disease group，respectively. There was statistical significance between the two groups. Conclusion：TLR9 gene and its 1237T / C polymorphism are closely related to cardiovascular diseases.