Background Organ preservation keeps the quality of the organs under prolonged ischemia.Continuous machine perfusions are gaining an important position in clinical research and practice.The aim of this study was to evaluate the protective effect of continuous hypothermic machine perfusion transport system (AirdriveTM) on cold ischemic injury of canine kidney.Methods Ten kidneys of five healthy preserving canines were taken out after general anesthesia.Five kidneys were stored using common cold preservation (CCP group) by immersing it in the organ preservation solution,mixed with water and ice,and kept in a cold room at 4℃.The other five kidneys were stored using continuous machine perfusion preservation (CMP group) and were placed into the AirdriveTM continuous machine perfusion device at room temperature.The renal tissues were examined by histopathology,electron microscopy,and mitochondrial activity check at different time points.Results Histologic sections showed that the structures of the ten renal tissues were similar during the first 24 hours.After 48 hours,the CCP group showed more pronounced changes,as the renal tubular epithelial cells were more obvious than those in the glomeruli.Oxygen consumption rate of state Ⅲ and Ⅳ respiration in the CCP group decreased after 12-48 hours and increased at 48 hours,respectively,when compared to the CMP group (P ＜0.05).Cortex respiratory control ratio and phosphorus oxygen ratio were significantly higher in the CMP group at 48 hours.Conclusion With prolonged storage time,the effect of continuous hypothermic machine perfusion transport system is better than that of common cold preservation on canine kidney.