Objective:To determine the association of plasma vascular endothelial growth factor(VEGF) and tissue kallikrein (TK) levels with coronary artery stenosis degree in coronary artery disease patients. Methods:According to coronary angiography,the patients were stratified as 50% to 69% stenosis in one artery (group 1,n = 32),70% to 99% stenosis in one artery and (or) 50% to 99% stenosis in two or three artery (group 2,n = 29),total occlusion in one and(or) multi-artery(group 3,n = 25) and no stenosis (control,n = 24). Plasma TK and VEGF concentrations were measured by ELISA. Results:TK augmented from (781 ± 63) pg/ml in no stenosis to (1 900 ± 461) pg/ml in group 1,(2 203 ± 268) pg/ml in group 2 and (4 823 ± 1 005) pg/ml in group 3. VEGF level was (54.75 ± 23.22) pg/ml in no stenosis,(54.29 ± 23.22) pg/ml in group 1,(63.00 ± 26.72) pg/ml in group 2 and (71.27 ± 17.86) pg/ml in group 3. Linear multivariate stepwise analysis showed that TK level was independently associated with coronary artery stenosis degree(P < 0.001) after adjusting for hypertension(P = 0.990),diabetes mellitus(P = 0.574) and smoking(P = 0.561). No association was found between VEGF level and obstruction grading. A threshold of 1 725 pg/ml provided the maximized predictive value of total obstruction. Conclusion:Plasma TK level was significantly higher in the presence of coronary artery disease. TK level was independently associated with coronary artery stenosis grading. TK measurement may be useful for the diagnosis of coronary artery stenosis grading.