To investigate the plasma placental growth factor (P1GF) level of patients with coronary artery disease (CAD), and the correlation between plasma P1GF level and coronary lesion severity.The study population consisted of 48 patients with CAD (proved by angiography, CAD group) and 28 normal controls (control group). Plasma P1GF was determined by an enzyme linked immunosorbent assay (ELISA). The lesion severity of coronary artery was assessed by Gensini coronary scoring system, the correlation between plasma P1GF level and coronary lesion severity was evaluated.The plasma PIGF level in CAD group was significantly higher than that in the control group C(9. 16+/-4. 09) ng/L vs (3. 64+/-1. 90) ng/L, P< 0. 01). A significant positive correlation was found between coronary lesion severity score and plasma P1GF level (r=0. 78, P<0. 01).The detection of plasma PIGF may be helpful to the early diagnosis of CAD and the evaluation of coronary lesion severity.