Abstract: To investigate the relationship between the clinical expression and ultrastructural pathology of internal organs in SARS. The autopsy specimens included lungs(8 cases) , hearts(4 cases), livers(4 cases), spleens(3 cases), kidneys(5 cases) and lymph nodes(3 cases) obtained from SARS cases. These organ samples were examined with light and electron microscope. The examination result shows: the wall of alveolus becames thicker; some of the inflammatory cells and fibrin seeped to the alveolar sac as well as lung interstitial; the fibril of cardiac muscle broke and mitochondria swelled; the lymph cells necrosis and membrane were destroyed in the spleen and lymph node. Some pathogen particles were observed in certain organs under the electron microscope. The SARS pathogen as a causative factor of the disease causes the immunopathological reaction. This reaction leads to the damage of the human body, especially to the damage of the lung, heart and immunity organs.

Key words: SARS, organs, pathology, ultrastructure