Abstract: Objective To study the cell proliferation and cell cycle distributions of EBV-positive NK/T cell lymphoma cell line (HANK1 cells) after silencing their EBNA1 expression, and to investigate the potential role of elimination of EBV infection on the treatment of EBV-associated NK/T cell lymphoma. Methods EBNA1 expression was silenced in HANK1 cells using RNA interference (RNAi) strategy, and the expression of EBNA1 was evaluated by means of Western blot.The cell cycle distributions and apoptosis were detected using flow cytometry. Results Suppressing EBNA1 expression caused cell cycle arrested at G1 phase, induced cell apoptosis and inhibited cell proliferation in EBV-positive HANK1 cells. Conclusion Elimination of EBV infection may be a good therapy for patients with EBV-associated NK/T cell lymphomas.