With glucocorticoid receptor (GR) blockade by RU38486, a competitive antagonist of GR, the change in contents of FITC labeled albumin (FITC-albumin) in pulmonary and renal tissue in scalded rats have been measured to study the changes in vascular permeability. The result showed that the contents of FITC-albumin in pulmonary and renal tissue in the scalded rats were markedly higher than those of the controls (lung: P < 0.05, kidney: P < 0.001). When the scalded rats were given GR blockade, the contents of FITC-albumin in pulmonary and renal tissue were significantly higher than those of rats with scald only (P < 0.05). The results indicated: (1) the pulmonary and renal vascular permeability in scalded rats was markedly enhanced; (2) GR blockade might aggravate the increase in vascular permeability caused by scald, so that the protective effect of glucocorticoid (GC) on vascular permeability seemed to be reversed.