Objective To explore the relationship between blood lipids and the severity of coronary artery disease. Methods A total of 4 751 patients with chest pain were divided into two groups according to the results of coronary angiography: coronary artery disease group (n=3 402 stenosis in one main branch stenosis≥50%) and control group (stenosis<50%, n=1 349). According to the number of coronary artery stenosis, the coronary artery disease group was divided into three subgroups (group 1: 1 branch stenosis; group 2: 2 branch stenosis;and group 3: 3 or more than 3 branch stenosis).The serum total cholesterol (TC),triglycefides (TG),high density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were determined and LDL-C/HDL-C was calculated.The relationship between lipids and the severity of coronary artery stenosis was analyzed by Spearman correlation analysis, and the risk factors of coronary artery disease were analyzed by multiple-stepwise logistic regression analysis. Results The levels of TG, TC, LDL-C and the ratio of LDL-C/HDL-C in the coronary artery disease group were significantly lower than those in the control group (P<0.01). LDL-C/HDL-C ratio increased with the increase of diseased branches in the disease group (P<0.001), and the number of diseased branches was positively correlated with the ratio of LDL-C/HDL-C (R=0.25, P<0.01). Logistic multiple regression analysis showed that high LDL-C/HDL-C level was an independent risk factor for coronary heart disease. Conclusion LDL-C/HDL-C ratio is an independent risk factor for coronary heart disease and it is positively correlated with the severity of coronary artery lesions.