The invention belongs to the field of PCR detection kits, and relates to application of a mutation site combination selected from an EB viral genome in preparation of kits for predicting attack risk of nasopharynx cancer. Mutation sites are loc162215, loc162476 and loc163364. The invention further provides a kit for predicting attack risk of nasopharynx cancer based on the mutation sites of the EBviral genome. The kit comprises a PCR amplification primer and a single-base extension primer which are used for detecting the combination of the three mutation sites of the EB viral genome, and themutation sites are loc162215, loc162476 and loc163364. The kit for predicting attack risk of nasopharynx cancer based on the combination of the three mutation sites can be constructed, the relative risk degree of individual suffering of nasopharynx cancer is estimated, and the kit is suitable for population screening of a high nasopharynx cancer incidence area and has positive guidance significance and important application value on tumor prevention, early diagnosis and treatment for tumors and prognosis improvement.