Objective:To screen and identify autoantibody biomarker to diagnose patients with nasopharyngeal carcinoma (NPC).Methods:Candidate autoantibodies against tumor-associated antigens were identified from NPC CNE2 cells using serological proteome analysis. Levels of candidate autoantibody biomarkers were measured by enzyme-linked immunosorbent assay (ELISA) in 50 patients with NPC and 80 normal controls recruited from the Cancer Hospital of Shantou University Medical College between July 2014 and January 2015. Receiver operating characteristic curve (ROC) was employed to evaluate diagnostic efficacy.Results:Serological proteome analysis showed that sera from patients with NPC yielded a positive spot, of which was identified as enolase 1 (ENO1). ELISA results showed that the level of serum autoantibody against ENO1 in patients with NPC was significantly higher than that in normal controls [0.165 (0.088, 0.378) vs. 0.100 (0.054, 0.117), Z=4.077, P<0.001]. With the optimum diagnostic cutoff of 0.164, ROC curve showed the diagnostic sensitivity and specificity of autoantibodies against ENO1 were 52.0% and 90.0%, respectively. Measurement of autoantibody against ENO1 demonstrated a positive rate of 75.0% for early stage NPC. Conclusion:Autoantibody against ENO1 may be a potential diagnostic biomarker for NPC.