Aim To investigate the value of the ratio of systolic blood pressure (rSBP) using treadmill exercise test in diagnosing coronary heart disease (CHD). Methods Ninety-nine patients (56 with CHD, 43 without CHD) underwent treadmill exercise test and selected coronary angiography. Data were analyzed and the sensitivity, specificity, accuracy of rSBP and traditional index were compared. Results The sensitivity, specificity and accuracy of the ratio of systolic blood pressure were 53.6%, 83.7% and 66.7% respectively, while those of the traditional index were 91.1%, 55.8% and 75.8% respectively; The sensitivity of rSBp>0.91 in diagnosing single vessel disease, double or multi-vessel disease increased gradually, lower than that of traditional index. Regression analysis showed a significant relationship between peak HR and pre-exercise HR (r=0.442, p<0.001)and between peak BP and pre-exercise BP (r=0.578, p<0.0001). Conclusions The ratio of systolic blood pressure in exercise test can predict coronary artery disease and its severity. Its sensitivity was lower than that of traditional index, but specificity was higher than it.