Abstract： Objective To summarize the clinical features of severe acute respiratory syndrome (SARS) and to discuss diagnosis and management of the disease.Methods A retrospective study was conducted on 78 cases of SARS referred to the Guangzhou Institute of Respiratory Diseases (GIRD) between December 22, 2002 and near the end of March 2003. Items reviewed cover all data concerning clinical manifestations, laboratory investigation and radiology.Results The patients in the study consisted of 42 males and 36 females, aged 20 -75 yrs (mean age 37. 5 +11.6 yrs), including 44 affected health-care professionals. Clinical symptoms seen in the group were fever (100. 0%), cough (88. 5%), and dyspnea (79. 5%). There were 12 cases (15. 3%) with WBCs ＜4.0×109/L, 49 cases (62. 8%) ranging between (4. 0 -10. 0) ×109/L and 17 cases (21.8%) over 10. 0 × 109/L. The average was(7. 58 ±4. 96) × 109/L, with 0.75 ±0. 14 (neutrophil) and 0.18 ±0.11 (lymphocyte). Chest films and CT scanning revealed changes related to pneumonia. The transmission of the disease was likely via close contact with contagious droplets.The prevalences of acute lung injury (ALI, in 37cases ) and acute respiratory distress syndrome (ARDS, 21 out of 37 cases ) were considerably high among the patients. Seven patients who developed ARDS complicated with multiple organs dysfunction syndrome (MODS) died.Conclusions A history of close contact, fever, sign of pneumonia by X-ray and normal-to-lowered WBC counts are favorable for the diagnosis of SARS. Recognition of All as the important index for critical SARS and comprehensive supportive management are of paramount in decreasing the mortality of the disease.