Abstract： A case of dermatomyositis coupled with extensive calcinosis is reported. A 25-year-old male presented with a 10-year history of dermatomyositis. Two years prior to the presentation, subcutaneous calcinosis emerged on the waist, and rapidly involved the trunk and limbs with limited mobility. On admission,the symptom of amyasthenia was remarkable with extensive prunosus and edematous macules all over the body surface, many large firm irregularly-sized subcutaneous masses on the trunk and limbs, limited mobility of knuckles in the flexed posture. There was also a marked increase of serum creatase. After treatment with prednisone, methotrexate, hydroxychloroquine for 4 weeks, an evident improvement was observed in the lesions and amyasthenia along with a reduction in serum creatase level. The use of diltiazem was attempted to manage calcinosis in this patient, who was still under follow up till the time of this writing.