Objective: To observe the correlation of Epstein-Barr virus (EBV) infection and COX-2 and p-glycoprotein (P-GP) in non-small cell lung cancer (NSCLC). Methods: Seventy-two specimens of NSCLC patients were the NSCLC group and 20 specimens of benign lung lesions were the control group. Partial sequence of BamHI-W genome of EB virus was measured by PCR and COX-2 and P-glycoprotein (P-GP) were detected by immunohistochemical methods in the two groups. Results: COX-2 positive rate was higher in NSCLC group than the control group (55.6% vs 15.0%, χ²=10.342, P=0.001). Compared with the COX-2 negative patients, the COX-2 positive patients had a higher proportion of lymph nodes metastasis (55.0% vs 28.1%, χ²=5.237, P=0.022). P-GP positive rate was higher in the NSCLC group than the control group (26.4% vs 0%, χ²=6.651, P=0.010). EB virus-positive rate was significantly higher in the NSCLC group than the control group (55.6% vs 30.6%, χ²=9.177, P=0.002); compared with EBV negative patients, EBV positive patients had a higher proportion of lymph node metastasis (57.5% vs 25.0%, χ²=7.659, P=0.006). COX-2 positive rate was higher in the EBV positive patients than the EBV negative patients (67.5% vs 40.6%, χ²=5.200, P=0.023). Conclusion: The effect of EBV infection on the occurrence and development of NSCLC may be related to the expression of COX-2, but it is not directly related to multidrug resistance of lung cancer.