Objective:To evaluate the diagnostic value of quantitative assay of EB virus specific antibodies to VCA-IgA and EA-IgA on diagnosing and screening of EB virus related nasopharyngeal carcinoma (NPC). Methods:The test panel consisted of 228 sera from NPC patients and 102 sera of healthy controls. For each specimen,immunoglobulin A antibodies to EBV-specific VCA(viral capsid antigen) and EA(early antigen) were quantitatively tested with enzyme linked immune absorbed assay respectively. Compared with the clinical pathologic diagnosis,the accuracy,sensitivity,specificity and cut-off value of each biomarker were analyzed. Results:The mean value of EB virus specific VCA-IgA and EA-IgA antibodies were 15 U/mL and 11.5 U/ml among healthy population;56.5 U/ml and 63.5 U/ml among NPC patients,each one’s level was significant higher in NPC patients than that in healthy population. VCA-IgA and EA-IgA can be used in diagnosing NPC accurately with 0.903 and 0.948,area under the ROC curve respectively. Through ROC curve analysis,the best cut-off values of VCA-IgA and EA-IgA were 30 U/mL and 23 U/ml. At this level,the sensitivity and specificity for diagnosing NPC were 84.9% and 66.8% for VCA-IgA,87.9% and 91.1% for EA-IgA,and 92% and 91% for combined determination. Conclusion:Quantitative detection of VCA-IgA and EA-IgA antibodies with ELISA method is very valuable in diagnosing NPC,especially combined determination.