Abstract: Coronary heart disease(CHD) is a common and frequently occurring disease which seriously threaten the health of human beings. So diagnosing CHD early and assessing the cardiac risk accurately and non-invasively that is a clinical problem which is urgent need for solving. Although the effectiveness of risk assessment algorithms have been proved by lots of clinical trials, but still has some limitations. The combination of myocardial perfusion imaging and coronary artery calcium score is promising in CHD diagnosis and cardiac risk assessment.