Lower paraoxonase (PON1) activity and higher oxidized low-density lipoprotein (oxLDL) levels are main risk factors of coronary heart disease (CHD). The aim of this study is to observe the characteristics of coronary artery lesions in CHD patients with or without hyperglycemia and relationships between coronary artery lesions and oxLDL levels as well as PON1 activity. Two hundred and eighty-four participants were divided into four groups according to their coronary angiographies and fasting plasma glucose levels: CHD+diabetes mellitus (DM) (n=46); CHD+impaired fasting glucose (n=62); CHD+normal fasting glucose (NFG) (n=86); healthy control group (n=90). The CHD+DM group had more diffuse lesions, higher frequency of severe coronary stenoses or total occlusions and more multivessel lesions than those with NFG. PON1 activity in the CHD+NFG group was lower than that in control participants (P<0.05), and much lower in the CHD patients with hyperglycemia (DM and impaired fasting glucose) (P<0.01). OxLDL levels in the CHD+DM group were higher than in the CHD+NFG group (P<0.05). In the CHD patients with hyperglycemia, the patients of multivessel lesions had higher oxLDL levels than those of single-vessel lesions (P<0.05) and the patients of severe stenosed vessels had obviously lower PON1 activity than those of mild and moderate stenosed vessels (P<0.01), whereas oxLDL levels were higher in the patients with diffuse lesions than those with focal lesions(P<0.05). In the multivariate analysis, the patients in the highest quartile of oxLDL level had an increased likelihood of having multivessel lesions or diffuse lesions compared with those in the lowest quartile [odds ratio (OR)=49.46, P=0.001; OR=34.30, P<0.001, respectively] whereas there was a negative correlation between two upper quartiles of serum PON1 activity and the likelihood of severe stenoses or total occlusions among the CHD patients with hyperglycemia (the top quartile, OR=0.14, P=0.008; the third quartile, OR=0.22, P=0.033). Lower PON1 activity and higher oxLDL levels may be predicting factors that denote diffuse, severe or multivessel disease in CHD patients with hyperglycemia.