AIM:To investigate the diagnosis and treatment of acute retinal necrosis syndrome (ARNS).·METHODS:The manifestation,diagnosis,treatment and prognosis of 64 eyes in 56 cases of ARNS from Jan.2003 to Jan.2009 were retrospectively analyzed.·RESULTS:After treatment,visual acuity improved in 37 eyes (58%).Final visual acuity was lower than 0.05 in 23 eyes (36%).Signs were controlled in 58 eyes (91%).·CONCLUSION:The diagnosis of ARNS should be mainly based on clinical manifestation,fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA).Early and sufficient treatment with antiviral agents,corticosteroid and prophylactic laser photocoagulation,sometimes vitrectomy are necessary to control the disease.