Objective To investigate the relevance of microalbuminuria(MA) to the severity of coronary lesions in patients with coronary heart disease, to investigate whether microalbuminuria (MA) can be related to the prediction of coronary artery disease and its severity. Methods 330 consecutive patients with CHD were enrolled, 194 males and 136 females (mean age 66±11) . All patients underwent coronary artery angiography (CAG).The severity of coronary artery disease (CAD) was evaluated by Gensini scores and assessed by the numbers of vessel disease and microalbuminuria expressed by the albumin to creatinine ratio (ACR).The patients were divided into two groups: the CHD group and the group without CHD .The clinical features and ACR between the two groups were compared, and correlations of microalbuminuria and severity of coronary artery disease were analyzed. Results CHD patients had higher MA positive rate than non-CHD patients (29.9% vs 3.0%, P＜0.01).MA positive rate increased progressively with severity of CAD and the numbers of vessel disease. The difference had statistical significance. MA was independent risk factor of CHD(P=0.045). Conclusion Micoalbuminuira is associated with coronary heart disease(CHD); micoalbuminuira is associated with the severity of coronary lesions in patients with CHD and is an independent predictor of CAD. Micoalbuminuira is an independent risk factor of CHD . Micoalbuminuira can be used to screen the high risk CHD population and evaluate the severity of CHD.