Abstract: Objective; The effect of human nasopharyngeal carcinoma cells (NPC)on proliferation transfected by EBV- LM P gene were studied. Methods; NPC cell line (CNE 1)as target, Electroporation was used to transfect EBV-LMP gene and the vector into CNE1 cells. In vitro, the proliferation changes of transfectants were measured by proliferation experiment, clone forming, FCM method and PCNA test. Results The proliferation experiment and clone forming results showed that, the LMP can contribute to increase the proliferation ability of NPC CNE1 cells, treatment group relative to control group and negative control group,p<0.01,FCM method test the cell cycle results show that, cells on Sphase is 34.9% in the treatment group,The PCNA positive rate of treatment group cells sufficiently increased,p<0.01.The results of transplant of CNE1 and transfectant in nude mice showed; The latent period and internal doubling time of transplant tumor of LM P expressive cell line was sufficiently shorted, P<0.01tumor formation rate and mass weight increased, P<0.01/0.05. Conclusion:The EBV-LMP can increase the proliferation ability of NPC CNE1 cells.The results suggests that EBV-LMP may have a important role in the development of NPC.