Objective To investigate the feasibility of magnetic resonance diffusion tensor imaging (MRDTI) technique in displaying myocardial fiber architecture. Methods In five ex vivo swine heart, diffusion tensor imaging (DTI) was acquired in 25 directions within 2 hours after excision. The myocardial fiber was reconstructed by using brain white matter tractography algorithm to display its course, distribution and arrangement. Results In the swine heart 1 hour after excision, MRDTI revealed that the arrangement of the myocardial fiber had certain continuity. It spiraled and twisted to form the left and right ventricle. The divection of general myocardial fiber in the left ventricle was vertical below endocardium, horizontal below epicardium and oblique in stratum medium, which is consistent with the theory of ventricular myocardial band. Conclusion MRDTI can reveal the myocardial fiber architecture, showing its integrity and arrangement, and at some level confirming the theory of ventricular myocardial band.