Objective  To investigate the relationship between dynamic changes in chest X-ray and therapy to severe acute respiratory syndrome (SARS).Methods  The onset time, site, range, and other imaging features of pulmonary lesions in chest radiograph were observed in seven patients with SARS,and their relationship with the therapy of corticosteroid and albumin plus frusemin was studied.Results  Abnormal image appeared in chest X-ray in all patients with the onset of the disease.Both lungs were involved and multi-lobe pathological changes were noted in six patients.Chest X-ray radiograms showed progressive changes,which was most severe on the 8    th～10    thday after the onset.Corticosteroid was applied to four patients,but it did not relieve pulmonary edema.The infiltration absorption was obvious with the medication of albumin plus frusemin in five patients.Conclusions  For sars patients abnormal image in chest X-ray appears very early and on a large scale,while it progress rapidly.Its shown that corticosteroid has no marked effect to interfere the progression of the disease.Albumin plus frusemin could significantly relieve pulmonary edema.