Abstract： Objective To observe the clinical features of acute retinal necrosis syndrome (ARN).Methods The clinical data of 84 patients (98 eyes) with ARN were retrospective analyzed.The patietns had undergone the examinations of best visual acuity,intraocular pressure,B-scanning,slit-lamp biomicroscope,preset lens,direct and (or) indirect ophthalmolscope,and trihedral reflector;fundus fluorecein angiography had been performed on the patients with clear refracting media.Some of the patients had undergone polymerase chain reaction (PCR) to dectet the types of the causative virus.Medication,laser photocoagulation,and vitreous surgery had been performed on the patients after the diagnosis was confirmed.The visual acuity and the change of ocular fundus had been followed up;the average follow-up was 24.1 months.Results The average age of the patients at the onset was 42.8 years with the bilateraleye rate of 16.6% and retinal-detachment rate of 57.1%.There were 53.5% and 35.5% patients had the final visual acuity of＞0.02 after 6 and 12 months,respectively.Better prognosis was found in patients diagnosed within 2 weeks and second involved eye.Varicella zoster virus DNA was identified in 15 patients and herpes simplex virus 1 was found in 3.Conclusions ARN is an acute disease with high incidence of retinal detachment.Serious retinal vasculopathy always happens at the late stage,and the prognosis is poor.Diagnosis in early stage is important and application of PCR will do contribution to the right diagnosis.