Background Increased level of glycated hemoglobin(HbA1c) is associated with higher incidence of coronary artery disease(CAD) in the diabetics. However, the relationship between HbA1c and the risk of coronary artery stenosis in the non-diabetics is controversial. Methods A retrospective research was conducted on 338 enrolled participants who have undergone 2 times of coronary angiographic examination within the past year. Clinical and laboratory variables at the initial and the second time of admission were collected. According to the initial median HbA1c level, all participants were divided into two groups named lower and higher groups. The relationship between HbA1c level and the risk of coronary artery stenosis over time was evaluated. Results The initial values of HbA1c in lower and upper groups were 5.78 ± 0.35% and 6.21 ± 0.32%(P < 0.05). As compared to the lower group, the percentages of male and smoking participants, and the serum level of CRP were significantly higher in the higher group(P < 0.05). Other traditional risk factors were comparable between the two groups.There were 54.2% and 55.2% participants with single vessel stenosis, and 45.8% and 44.8% with multiple vessel stenoses, respectively in the two groups without significant difference. The second time of admission, were 308.5± 25.4 days(lower group) and 300.7 ± 30.1 days(higher group) from the initial admission. Although no significant changes of HbA1c level were observed when compared to initial, HbA1c level in the higher group was still significantly higher in comparison to the lower group(6.24 ± 0.39% vs. 5.80 ± 0.36%, P = 0.008). The percentage of new coronary artery stenosis(≥ 50% stenosis) was higher in the higher group than that in the lower group(41.7% vs. 32.3%, P < 0.001). Multivariate regression analyses suggested that HbA1c remained independent factor associated with coronary artery stenoses after extensive adjustment for risk factors. Conclusion In the nondiabetics, increased baseline HbA1c level portends the risk of coronary atherosclerotic plaque progression over time. Background Increased level of glycated hemoglobin (HbA1c) is associated with higher incidence of coronary artery disease (CAD) in the diabetics. However, the relationship between HbA1c and the risk of coronary artery stenosis in the non-diabetics is controversial. Methods A retrospective research was conducted on 338 enrolled participants who have undergone 2 times of coronary angiographic examination within the past year. Clinical and laboratory variables at the initial and the second time of admission were collected. According to the initial median HbA1c level, all participants were divided into two Results The initial values ​​of HbA1c in lower and upper groups were 5.78 ± 0.35% and 6.21 ± 0.32% (P <0.05) As compared to the lower group, the percentages of male and smoking participants, and the serum level of CRP were significantly higher in the higher than that of the higher group (P <0.05). Other traditional risk factors were comparable between the two groups. There were 54.2% and 55.2% of participants with single vessel stenosis, and 45.8% and 44.8% with multiple vessel stenoses, respectively in the two groups without significant The second time of admission, were 308.5 ± 25.4 days (lower group) and 300.7 ± 30.1 days (higher group) from the initial admission. Although HbA1c level was observed when compared to initial, HbA1c level in the higher The percentage of new coronary artery stenosis (≥ 50% stenosis) was higher in the higher group than that in the lower group (41.7% vs. 32.3%, P <0.001). Multivariate regression analyzes suggested that HbA1c inactive independent factor associated with coronary artery stenoses after extensive adjustment for risk factors. Conclusion In the nondiabetics, increased baselineHbA1c level portends the risk of coronary atherosclerotic plaque progression over time.