Aim To explore the correlation between plasma HDL function and coronary artery stenosis and plaque property in coronary artery disease (CAD) patients with normal HDLC levels (≥1.03 mmol/L). Methods 129 cases suspected CAD with normal HDLC levels in Yichang Hospital of Traditional Chinese Medicine from October 2015 to December 2017 were enrolled, and grouped according to the severity of coronary artery stenosis and plaque property by 64-slice spiral CT coronary angiography (CTA). Paraoxonase 1 (PON1) activity and HDL oxidation/antioxidant index were detected. Results Compared with non-CAD group, plasma HDLC level and PON1 activity were significantly decreased, and HDL oxidation/antioxidant index was increased in the CAD group, showing an oxidized state, while ApoAI level had no difference. Although there were no difference in HDLC and ApoAI levels, PON1 activity was gradually decreased and HDL oxidation/antioxidant index was increased, accompanying with increased stenosis of coronary artery. The data also showed that PON1 activity of calcified plaque group was higher than that of soft plaque group and mixed plaque group. There is a correlation between PON1 activity and HDLC, HDL oxidation/antioxidant index. Conclusion PON1 activity as an index of HDL function may be a potential biomarker for assessment of the plaque property and severity of CAD.