To evaluate the coronary vasomotor tone in vasospasic angina, we compared the diameters of non-spastic segments of vasospastic group with those of control group. The internal diameters of each segment of three major coronary arteries were measured on the basal coronary angiogram, and nitroglycerin administration after provocation with ergonovine or acetylcholine. The vasospastic angina group consisted of 26 patients(20 males, 6 females, mean age of 54 years) and control group consisted of 25 patients (7 males, 18 females, mean age of 55 years). The basal coronary arterial diameters in vasospastic angina group were smaller than those in control group(p<0.05) except the distal segment of right coronary artery. The percent dilation ratio in vasospastic angina group was greater than that in control group(p<0.05). In vasospastic angina group there was no significant difference in the degree of constriction after provocation with ergonovine or acetylcholine between proximal and distal segment. These observations suggest that in vasospastic angina, basal coronary arterial tone is increased in the entire coronary arterial tree and the localized spasm may reflect local hyperrespon siveness.