Abstract: Objective: To investigate the risk factors leading to death for patients with dermatomyositis (DM).Methods: The clinical data of 156 patients with DM including 44 patients who had died were analyzed retrospectively.Results: The mortality rate was 22.2%,with the male accounting for 39.6% and the female 13.5% (P<0.01).The peak age of onset ranged from 56 to 65.The mortality rate in cases with acute onset and subacute onset was 33.3% and 29.5%,respectively,which was higher than that with chronic onset (12.3%) (P<0.05).Among the 44 cases who had died,29 cases had a disease course of less than 1 year and 37 cases less than 3 years,the mortality of which was higher than that over 3 years;18 of the cases were complicated with malignant tumors and 18 interstitial lung disease (ILD) (including 5 secondary infections);6 cases died of pulmonary infection and 2 unknown causes.The serum level of lactate dehydrogenase (LDH),γ-glutamyltransferase (GGT),erythrocyte sedimentation rate (ESR) and gamma globulin were higher in the patients with poor outcome than that in those with fine outcome (P<0.05-P<0.01).There were significant difference in arthralgia,fever and electrocardiographic abnormality between patients with poor outcome and fine outcome (P<0.01).The differences in serum levels of CK,positive anti-ANA,positive anti-dsDNA,positive anti-Jo-1 antibody and the skin rashes were not significant between the two patient groups (P>0.05).Conclusions: These data indicate that the mortality of dermatomyositis occur mostly in the first 3 years of onset,especially the first year.The risk factors leading to death for DM patients are malignancy,ILD,pulmonary infection,acute and subacute onsets,old age,maleness,arthralgia,fever and electrocardiographic abnormality.The serum levels of GGT,LDH,ESR and gamma globulin have prognostic value for the DM patients.