Objective:To observe the change of the morphological structure in lung perfused with raffinose-low-potassium dextran solution(R-LPD-蒺S). Methods:The 20 pig donor lung perfused with low-potassium dextran solution(LPD-蒺S) and R-LPD-蒺S was observed by light microscope, electronic microscope and immunohistochemistry. Results:Morphologic changes of the structure in the tissue cell were gradually obvious along with time. After 24 h of preservation, the tissue of donor lung perfused with LPD-蒺S showed a decreased number of intact type Ⅱ pneumocytes and significant cellular necrosis. Interstitial and alveolar edema with interstitial macrophage infiltration was also observed. Alveolar capillaries were collapsed. In contrast, R-LPD’S lungs showed only mild alterations such as minor interstitial edematous expansion, fewer damaged cells, and minor capillary injury. Conclusion:R-LPD’S exerts a cytoprotective effect on preservation of donor lung during pulmonary grafts, and it should be superior to LPD-S for this purpose.