Objective To investigate the safety, efficacy of the surgery and the characteristics of the blood flow after coronary artery bypass graft (CABG) surgery using bilateral internal mammary artery (BIMA) to analyze the early operative results, CT results and the graft flow. Methods From December 2015 to July 2016, 52 patients (46 males, 6 females) with an average age of 56.6±6.8 years, underwent CABG using bilateral internal mammary artery. All the operations were carried out under extracorporeal circulation, both internal mammary arteries were obtained with pedicle and the bypass path was designed according to the target vessels. After the anastomosis was completed, the graft flow was measured using Veri Q system. The CT angiography of coronary artery was completed before discharge. Perioperative outcomes, early CT outcomes, and blood flow of grafts were analysed. Results There was no operative mortality. The average operation time was 4.7±0.6 hours, average cardiopulmonary bypass time was 114.8±20.6 minutes, average cross-clamping time was 82.8±17.6 minutes, average mechanical ventilation time was 17.6±10.5 hours and average ICU stay was 2.7±1.8 days. The mean number of distal anastomosis was 4.6±0.8. One patient suffered sternal complication and poor wound healing and then receieved debridement as well as suturing. Other patients discharged without surgical complications. The average flow of left internal mammary artery (LIMA) graft was 28.1±11.4 ml/min with a mean pulsatility index (PI) of 2.2±0.6. The average flow of right internal mammary artery (RIMA) was 27.3±12.0 ml/min with a mean PI of 2.4± 0.8. The mean flow of great saphenous vein was 41.5±21.5 ml/min with a mean PI of 2.2±0.7. There was no significant difference in the mean flow between LIMA and RIMA (P=0.978). The mean flow of the great saphenous vein was significantly higher than that of RIMA and LIMA (P=0.000). CT angiography showed no stenosis. Distal anastomosis of 7 vein grafts and 5 artery grafts was demonstrated shallow in CT angiography and 2 vein grafts were undemonstrated, suggesting occlusion. Conclusion The use of BIMA for CABG is safe with less complications. RIMA flow is equivalent to LIMA flow. RIMA with no stenosis and occlusion of artery grafts in the early stage, therefore is the ideal and stable coronary bypass graft.