Objective: To establish the rabbit model of ischemia lung - perfusing protective solution through pulmonary artery - reperfusion injury in vivo, to study the protective effect of hypothermia washing-RBC solution perfused through pulmonary artery on ischemia-reperfusion injury of the rabbit lung in vivo and its mechanism.Method: Twenty-one New Zealand rabbits were selected from the animal experiment center of West district of Shandong university and were established the model of ischemia lung - perfusing protective solution through pulmonary artery -reperfusion injury in vivo. Three of those rabbits were killed , blood were made into washing RBC with ATS system. The rest eighteen rabbits were randomly divided into three groups(each n=6). Group Ⅰ (control group): the rabbits were only opened chest and not made into ischemia-reperfusion injury of the lung; group Ⅱ (ischemia-reperfusion group): the left hilum of lung( pulmonary artery, pulmonary vein, bronchus) was fully blocked up 60 min and reperfused 90 min; group Ⅲ(protect group): pulmonary artery was blocked up, 4-8 ℃ washing-RBC solution (pure RBC, 5% glucose 0.35g/ 100ml, Dexctran40 2g/100ml, methylprednisolone 5-10mg/kg, anisodamine 0.5mg/kg, trinitroglycerin 5mg/100ml) was perfused 60 min (0.25-0.5ml/ kg/min) through the far position of blocked pulmonary artery, then pulmonary artery was opened and reperfused 90 min. At different time the specimens were taken to detect blood plasma malondialdehyde(MDA) and arterial blood gas analysis, to calculate the