To confirm the effect of EBV encoded LMP1 on expression and activation of nuclear transcription factor, Ets-1 and extracellualr signal regulated kinase(ERK) involved in the process. The expression of p-ERK and Ets-1 were assayed with Western blot, and phosphorylation of Ets-1 was assayed with co-immunoprecipitation-Western blot. MEK1/ERK specific inhibitor PD98059 was used to confirm that ERK mediated the activation of Ets-1 by LMP1. The results showed that in nasopharyngeal carcinoma cell line, EBV-LMP1 enhanced the expression of Ets-1 and p-ERK, and phosphorylation of Ets-1 to some extent in time- and dose-dependent manner. With blockade of PD98059, expression of p-ERK induced by LMP1 decreased significantly, and expression and phosphorylation of Ets-1 by LMP1 decreased partly. These results suggest that expression and phosphorylation of Ets-1 by LMP1 was mediated partly by ERK.