Background: Although it plays a vital role in the whole process of various cardiovascular diseases, the characteristic immune changes of peripheral blood in patients with CAD have not been well recognized. This study aimed to determine the expression of differentially expressed immune-related genes (DE-IRGs) in CAD by screening three gene chips downloaded from the Gene Expression Omnibus (GEO) database. Methods: We downloaded CAD and Healthy groups’ information and IRGs from the GEO database and Immport database (ImmpDb) respectively. By R software, we processed GO and KEGG analysis to find out the function and main enriched pathway between two groups. LASSO method was used to identify genes for diagnostic testing. CIBERSORT analysis revealed the differential immune cell distribution. Finally, we verified the expression of these differential genes through an animal project.Results: 762 differentially expressed genes (DEGs) were identified in this process, which mainly enriched in infection, immune response and neural activity and might participate in the CAD process by affecting the extracellular matrix formation and receptor-ligand activity functions. In total, 58 DE-IRGs were subsequently obtained by overlapping the DEGs and immune-related genes downloaded from ImmpDb. Through LASSO regression, CCR9, CER1, CSF2, IL13RA1, INSL5, MBL2, MMP9, MSR1, NTS, TNFRSF19, CXCL2, HTR3C, IL1A, and NR4A2 among the 58 DE-IRGs were distinguished as peripheral biomarkers of CAD, which showed eligible diagnostic capabilities separately. These screened genes were then validated by an animal subject. The real-time PCR test showed that CCR9, CSF2, IL13RA1, and NTS had significant differences between the CAD model and healthy control samples, suggesting that they were promising diagnostic and therapeutic targets. Besides, CIBERSORT algorithm analysis showed that the immune-related cells existed characteristic distribution in CAD, which was discovered to have a close relationship with some specific DE-IRGs. Conclusions: In summary, we confirmed four peripheral immune biomarkers related to CAD and provided new potential targets for regulating the immune relevant mechanism, laying a foundation for further excavation of CAD immune mechanism.