All participants will be tested for EBV associated biomarkers, including EBNA1-IgA, VCA-IgA, BNLF2b total antibodies (P85-Ab) et al. For all male participants and P85-Ab positive female participants, EBV DNA in plasma will be tested. Screening positive participants will be followed up annually.

All subjects will also be followed by record linkage to Cancer Register and Population Register.

Sample selection

- Select communities of 20,000 to 40,000 populations in Zhongshan City and Wuzhou city as the investigators' fields.

Participants recruitment

• Subjects voluntarily attend this screening study Informed consent - Informed consent forms will be collected at the recruitment. Questionnaires.
• Face-to-face interviews are conducted by well-trained investigators.

Tests and follow up

• At initial screening, all participants will be tested for EBV associated biomarkers, including EBNA1-IgA, VCA-IgA, P85-Ab et al. And in males, EBV-DNA will be tested. Based on EBNA1-IgA, VCA-IgA, participants will be stratified into high, moderate and low risk. Screening positive include P85-Ab positive, high or moderate risk of NPC or EBV DNA positive. The rest will be screening negative.
• During the initial screening and following up, people with high risk or P85-Ab positive will refer to the diagnostic workup for NPC. Briefly, fiberoptic endoscopy and pathological biopsy will be performed by otorhinolaryngologists.
• Screening positive people not diagnosed as nasopharyngeal carcinoma in the first year will be followed up annually.
• EBV DNA single positive people will refer to the diagnostic workup for NPC in the third year of follow up.
• The rest of the blood samples will be stored at the biobank of Zhongshan People's Hospital for further research.
• All subjects will also be followed by record linkage to Cancer Register and Population Register.

Inclusion Criteria:

• Subject residents in Zhongshan City or Wuzhou City
• Subject has no medical record of nasopharyngeal carcinoma
• ECOG 0-2
• Subject is able to comprehend, sign, and date the written informed consent document to participate in the study.
• Subject has psychical condition and well consciousness, and also accept and cooperate with the follow-up of this study.

Exclusion Criteria:

• Subject has heavy cardiovascular, liver or kidney disease.
• Subject has contraindications to nasopharyngeal fiberoptic endoscopy.

30-69 years old healthy residences in Zhongshan City and Wuzhou City.