The paper had discussed and analyzed the pathogens and pathogenesis of SARS on the observation of 65 cases. SARS was named lung pestilence by TCM theory. The pathogens of SARS were plague and damp-heat evil. The key of SARS pathogenesis was closure of lung-qi. The disease attacked the qi phase at first

then nutrient and blood phases and finally transmitted to the pericardium reversely. The stagnation of damp turgidity and insufficiency of qi and ying were the results of the disease. In the high fever stage of SARS evil-heat was exuberant; the asthma stage

the lung was stagnated by damp turbidity; and the later stage

the insufficiency of qi and ying was the most important symptom. Because of the large dose of hormones were applied at the treatment of SARS by western medical physicians

many cases had the symptoms of exuberant heat and obstructive damp even in their convalescences. So the treatment of SARS with TCM should be stressed on clearing away heat and dispersing lung

resolving dampness and dredging collaterals on the basis of reinforcing qi and ying.