Objective To evaluate the titers of EV71 neutralizing antibody in donators' plasma,and to establish a high throughput screening method to screening anti-EV71 positive plasma for the production of EV7l-specific IVIG in practice.Methods The EV71 neutralizing antibody titers in plasma samples and in commercial IVIGs (intravenous immunoglobulins) were evaluated by micro-cytopathic effect neutralization test (MCPENT),and a selecting criteria was determined for screening anti-EV71 positive plasma.Then,a high throughput neutralizing method for screening plasma was established and a comparison with MCPENT was conducted.EV71-specific IVIG was prepared from screened anti-EV71 source plasma,and its neutralizing activity was evaluated in cell model and mouse model.Results The results of MCPENT showed that the titers of EVT1 neutralizing antibody were 1 ∶ 50 or above in 20％ of the source plasma,and reached 1 ∶ 180 after being pooled,approaching to the titer of commercial IVIG.In 480 samples,the coincidence rate between the established high throughput neutralizing method and MCPENT was 88.1％.The quality of prepared EV71-specific IVIG was complied with the national standard,and its neutralizing potency was 16 times of that of IVIG,suggesting EV71-specific IVIG had a significantly improved protecting effect on experimental neonatal mice.Conclusion The screening method and the screening criteria for EV71 specific plasma were successfully established.The established high throughput neutralizing method that was operated easily could be used for plasma screening in the development of EV71-specific IVIG.The prepared EV71-specific IVIG,whose neutralizing potency was significantly improved,showed a markedly protective effect on experimental neonatal mice,suggesting it might be very important for the prevention and treatment of handfoot-and-mouth disease.