Background and Aim: The cardiac syndrome X is an important clinical entity and has a good long-term outcome, however, is still remained troublesome due to uncontrolled chest pain for many cardiologists. The aim of this study was to elucidate the factors related to long-term outcome in cardiac syndrome X. Methods: 354 subjects(M:F=186:168, mean age:55 짹 11years) with chest pain and a normal coronary arteriogram were enrolled in the study. The coronary flow reserve (CFR) using transthoracic Doppler echocardiography(TTE) and adenosine or dipyridamole was estimated within 2 weeks after the coronary angiogram. We analyzed the long-term outcome via the telephone interview and compared the CFR with clinical data. Results: During the follow-up duration[45짹21 months (range 12-109 months)], 2 patients died due to non-cardiac cause. 137(71%) among 193 patients who responded the telephone interview were treated currently. Of these, the CFR was closely related to the HDL level(r=.319, p=.001), Hb level(r=-.195, p=.004) and Hct level(r=-.195, p=.040) By multivariate analysis, the independent factors related to a CFR<2.0 were the HDL level(OR:1.089, 95%CI: 1.025–1.156, p=.005), Hb level(OR: 5.008, 95%CI: 1.292–19.409, p=.020) and Hct level(OR: 16.609, 95%CI: 0.306–0.841, p=.009). Conclusion: Our results show the subjects with chest pain and normal coronary angiogram have a good long-term outcome and CFR <2.0 suggesting ischemic range is closely related to HDL cholesterol, Hb and Hct level.