Abstract: Objective: To investigate the correlation between diabetes and the formation of coronary atherosclerotic plaque in DSCT angiography. Methods: The patients underwent DSCT coronary angiography, on the basis of questionnaires, were divided into diabetes group (n = 300) and non-diabetes group (n = 300) first, then diabetes group, which was divided into two groups:group 1, duration of diabetes less than or equal to 5 years (n = 180) and group 2, duration of diabetes more than 5 years (n = 120). Two groups were observed and compared the incidence rate of plaque, distribution characteristics and types. Results: The incidence rate of 3 coronary artery vascular lesions was 27.5% in diabetes group and 20.6.0% in non diabetes group. Incidence rate of diffuse lesions was 43.8% in diabetes group, 17.4% in non diabetes group, the difference between the two groups were statistically significant (P ＜ 0.05). Comparison of the degree of coronary artery stenosis: Severe stenosis was 7.9% and occlusion was 4.8% in diabetes group; those were 3.7% and 1.9% respectively in non diabetes. Severe stenosis was 12.2% and occlusion was 7.8% in group 2; those were 0.93%, 0% in group 1, the difference between the two groups were statistically significant (P ＜ 0.05). Plaque types: occurrence rate of mixed plaque was 51.4% in diabetes group and 38.9% in non diabetes group. The incidence of non calcified plaque was 43.8% in diabetes group, 53.7% in non-diabetes group, the difference between the two groups were statistically significant (P ＜ 0.05). occurrence rate of mixed plaque was 63.3% in group 2 and 31.5% in group 1, The difference between the two groups were statistically significant (P ＜ 0.05). that both diabetes and duration of diabetes were independent risk factor for mixed plaque. Mixed plaque was increased with the duration of diabetes increasing through statistical analysis. Conclusion: DSCTCA can evaluate the relationship between the diabetes and coronary artery plaque. Coronary plaque involvement is wider, Luminal stenosis is more serious, Incidence rate of mixed plaque is higher and having more risk prone to cardiovascular events in diabetes, and will be more serious with longer duration of diabetes.