Background: Myocardial bridge(MB) is a relatively benign condition where a major coronary artery is engulfed by a band of muscle and narrows during systole, particularly during rapid heart rate. However, its clinical presentation overlaps with that of significant coronary artery disease(CAD) and it is occasionally associated with myocardial ischemia, infarction, cardiac arrhythmia, and even sudden death. So We investigated the changes and patterns of Tl-201 myocardial perfusion imaging as functional study in patients with MB. Subjects and Methods: We included 34 patients who had typical symptoms of angina and normal coronary artery but myocardial bridging of left anterior descending artery(LAD) as documented by coronary angiography from 2005 to 2006, June. They received the examination of echocardiography and Tl-201 myocardial single photon emission computed tomography(SPECT). And we analysed the changes and patterns of Tl-201 SPECT. Results: The mean age of subjects was 55.2 years and proportion of male was 52.2%. They had diabetes(31%), hypertension(34.8%), history of smoking(26.1%) and dyslipidemia(21.7%) as risk factors of CAD . Echocardiography found no regional wall motion abnormality and normal left ventricular function. The site of MB in LAD was mid(82.6%) and distal(17.4%). In the SPECT perfusion studies, 32 of 34(94.1%) subjects showed abnormal perfusion findings with reversible(56.5%), partial reversible(17.4%), reverse redistribution(13%), and persistent(8.7%) defects. Conclusion: Abnormal perfusion patterns are found on Tl-201 SPECT in patients with typical chest pain and MB. Although the clinical significance of these abnormalities is not exactly known yet, these may partly explain the angina which is complained despite normal coronary artery in patients with MB.