Abstract: To investigate the expression level of mRNA encoded by the TRF1 (telomeric repeat binding factor 1) and tankyrase 1 (TANK1 ) in cancer tissues and paired noncancerous tissue. Methods: A total of 40 patients including 29 males and 11 females with non- small cell lung cancer (NSCLC) underwent radical surgery. There were 20 cases of squamous cell carcinoma and 20 cases of adenocarcinoma in the group. The expression of TRF1 and TANK1 mRNA was measured by RTPCR. Results: TRF1 mRNA was significantly downregulated in cancer tissue compared to the paired noncancerous tissue (P<0.05). TANK1 mRNA was significantly upregulated in cancer tissue compared to the paired noncancerous tissue (P<0.05). In addition, the expression of TRF1 mRNA was significantly associated with the grade of tumor differentiation (P<0.05). No significant difference in the TRF1 mRNA level was found between the patients of different sexes or among different clinical stages, pathological subtypes and lymph node metastasis (P>0.05). Conclusions: Downregulation of TRF1 mRNA expression and upregulation of TANK1 mRNA expression occur in lung cancer tissue. TRF1 may play a significant role in cell differentiation in NSCLC.