Rhino-orbital mucormycosis was a rare, but mostly fatal fungal infection, usually found in poorly controlled diabetics or other immunocompromised hosts. This fungal infection begins from the nose, and rapidly spreads to the paranasal sinus (PNS), orbits and central nervous system(CNS), and finally extends to the entire organ. Early diagnosis and treatment is the only way to increase the survival rate. Herein Is reported We experienced a case of rhino-orbital mucormycosis, with type 1 diabetes mellitus, which was confirmed by a maxillary sinus biopsy. A 38-year-old male had been frequently treated for tonsillitis, but with no history of diabetes mellitus. He was admitted with mental change, accompanied by a fever, facial tenderness and swelling, with progressive visual acuity loss. During admission, CT and MRI of the in orbital area were performed. A biopsy in of the nasal cavity was also performed, and the mucormycosis was diagnosed through the pathological finding. The patient was treated with intravenous amphotericn B and an endoscopic antrostomy.