This research aimed at observing the veins of the hearts of 10 Tuj sheep by latex injection. The results documented that the veins draining the heart of Tuj sheep were the great and middle cardiac veins, the right cardiac veins, and the minute cardiac veins. The coronary sinus was determined to be the continuation of the left azygos vein, receiving the great and middle cardiac veins. The left marginal ventricular vein in one heart and the veins draining the left atrium in five hearts were observed to terminate in the coronary sinus. In one cadaver, venous blood of the left atrium was shown to be emptied both into the left azygos vein and the caudal vena cava. Moreover, the left distal ventricular vein was displayed to discharge the venous blood into the coronary sinus in five hearts and into the great cardiac vein in two hearts, yet was not present in three hearts. Venous blood of the left atrium near the aortic arch was displayed to empty into the cranial vena cava in two cadavers. There was another vein ending within the angle where the paraconal interventricular vein became the left circumflex vein, which reflected the angular vein present in the cat and horse. The right semicircumflex vein was seen to be constituted by the right marginal ventricular vein and the right proximal ventricular vein and the right conal vein. The right distal ventricular vein was determined to drain directly into the right atrium. There were also eminent anastomoses between the branches of the cardiac veins observed.