A recombinant retroviral vector containing Epstein-Barr virus (EBV) LMP1 antisense sequences was constructed to evaluate the posibility of gene therapy in nasopharyngeal carcinoma. The vector was packed with PA 317 cells as a pseudoretroviral one. Immunofluorescence examination showed it can evidently suppress the activation of B95-8 cell EBV. The inhibition rate was 71%. We have successfully using it to infect human poorly differentiated nasopharyngeal carcinoma cell line CNE-3, its growth was lowered down at a rate of 70%. The ability of clone formation in soft agar, tumorigenicity in nude mice of CNE-3 were markedly dropped. By Southern blot, there was high level of retroviral vector pZIP neo gene present in the transfection of tumor cells which confirmed that antisense virus LMP1 can suppress the growth of CNE-3 cells and the tumorigenicity in nude mice. Reversly it also confirmed the relationship between EBV and nasopharyngeal carcinoma and provided experimental basis for the gene therapy of the nasopharyngeal carcinoma.