Objective To investigate the significance of detecting serum thyrotropin receptor antibodies(TRAb) in patients with Graves disease or Graves ophthalmopathy.Methods Serum TRAb was measured using radioimmunoassay in 83 patients with Graves disease(group A),73 patients with Graves ophthalmopathy(group B).Patients with Graves ophthalmopathy were assessed using clinical activity score(CAS) and the severity of Graves ophthalmopathy was evaluated using NOSPECS Grade.Results Serum concentration of TRAb was positively correlated with the activity and severity of Graves ophthalmopathy,which was higher in patients with middle and serious Graves ophthalmopathy than that in those with slight Graves ophthalmopathy(P0.05).ConclusionSignificant increase of serum TRAb may be taken as one of the markers to predict the development and guide the treatment in the patients with Graves ophthalmopathy.