Background and Objective: With the increase of aging, osteoporosis and cardiovascular diseases are common diseases in middle-aged and elderly people. The purpose of this study is to explore the correlation between osteocalcin and coronary calcification.Methods: A total of 150 middle-aged and elderly physical examination subjects who had undergone coronary artery CT angiography (CTA) were selected as the research objects. The calcification score of the coronary artery was calculated according to the Agatston (AS) integral method, and the total score was divided into the coronary artery calcification group and the non-calcification group. The indexes of N-terminal midfragment of osteocalcin (N-MID), routine biochemical indexes and basic conditions of each patient were recorded.Results: In the comparison of general data between the non-calcification group and the calcification group, the differences in age(P<0.001), pressure difference (P = 0.01)and low density lipoprotein cholesterol (LDL-C)(P<0.001)were statistically significant, the differences in smoking history (P<0.001)and drinking history (P<0.001)were statistically significant, and the differences in N-MID (P<0.001)were statistically significant. Coronary artery calcification score (CACS) was correlated with age, pressure difference, LDL-C, N-MID, smoking history and drinking history. The four variables, age, LDL, N-MID, and smoking history, have certain effects on coronary artery calcification (CAC).Conclusions: In middle-aged and elderly people undergoing physical examination, N-MID is correlated with CAC and can be used as a predictive indicator.