Abstract: Objective:To investigate the clinical significance of detecting Epstein Barr virus (EBV) infection in evaluating recent curative and long-term effects in patients with extranodal natural killer (NK)/T-cell lymphoma. Methods:The EBV-DNA copies in the plasma of 109 patients, who were pathologically and immunohistochemically diagnosed with extranodal natural killer/T-cell lymphoma in the First Affiliated Hospital of Zhengzhou University between January 2011 and April 2014, were monitored via quantitative re -al-time polymerase chain reaction. Subsequently, the difference in recent curative and long-term effects between EBV positive and EBV negative patients was compared.Results:Among the 109 patients with extranodal NK/T-cell lymphoma, 34(64.2%) cases of EBV posi-tive patients were at the advanced stage (Ⅲ～Ⅳstages), and 22(39.3% ) cases of EBV negative patients were at the terminal stage ( Ⅲ～Ⅳstages). EBV positive patients who accompanied by B symptoms were 33(62.3%) , and there were21(37.5%) cases with B symptoms in EBV negative patients, the differences between stages and B symptoms were statistically significant. The attained objec -tive response rate of the EBV-DNA negative patients (34, 60.7%) was significantly higher than that of the EBV-DNA positive patients (22, 41.5%) (P<0.05). Similarly, the 2-year progression-free survival (PFS) rate of EBV negative patients was better than that of EBV positive patients (P<0.05). Conclusion:Detecting EBV in plasma has clinical significance in evaluating the recent curative effect and the 2-year PFS rate in patients diagnosed with extranodal NK/T-cell lymphoma.