Aim To assess the correlation between the peripheral blood T cell subgroup proportion and the degree of coronary atherosclerosis in patients with coronary heart disease to provide the evidence for the T lymphocyte mediating immune inflammation, and inducing plaque progression. Methods Fifty-seven patients were enrolled after routine and coronary angiography examinations between June 2012 and December 2012. The proportion of peripheral blood CD3⁺ cell in peripheral blood lymphocyte, and CD4⁺, CD8⁺ cell in the T lymphocyte, and CD4⁺CD25⁺Treg, CD4⁺CD28^－T cell in the CD4⁺T cells, were detected by flow cytometry using five-color fluorescent markers. Correlation between the peripheral blood T lymphocyte subgroup and the degree of coronary atherosclerosis （modified Gensini standard） was analyzed. Results The proportion of peripheral blood CD3⁺ cell in stable angina pectoris（SAP） group, unstable angina pectoris（UAP） group and acute myocardial infarction （AMI） group were significantly higher than those in control group （all P<0.05）. The proportion of CD4⁺ cell and CD8⁺ cell in UAP group and AMI group were significantly different compared with those in control group and SAP group （all P<0.05）. The proportion of CD4⁺CD25⁺ Treg and CD4⁺CD28^－ cell in UAP group and AMI group were significantly different compared with those in control group and SAP group （all P<0.05）. The peripheral blood CD3⁺ cell were positively correlated with Gensini score（r0.608,P<0.01）. The CD4⁺ cell were positively correlated with Gensini score （r0.624,P<0.01）. The CD8⁺ cell were negatively correlated with Gensini score （r－0.548,P<0.01）. The CD4⁺CD25⁺Treg were negatively correlated with Gensini score（r－0.617,P<0.01）. The CD4⁺CD28^－T cell were positively correlated with Gensini score（r0.399,P<0.01）. Conclusions T lymphocyte subgroup plays an important role in the developmant and progression of atherosclerosis, and has certain prospective value in the clinical evaluation of the severity of the coronary disease.