The expression of excision repair cross-complementing group 1 (ERCC1) and ribonucleotide reductase subunit M1 (RRM1) has been reported to relate with the survival and response of chemotherapy for lung cancer, especially non-small cell lung cancer (NSCLC). However, there is little information on the differences in their expressions and clinical significances between squamous cell carcinoma (SqCC) and adenocarcinoma (ADC). This retrospective analysis was performed on 100 patients diag-nosed as NSCLC pathologically from March 2011 in a teaching hospital. The quantified results of expression of ERCC and RRM1 showed that the mean IRS of ERCC1 and RRM1 were 4.77 and 3.54. Interestingly, the values of ERCC1 in male patients was higher than those of woman (4.94 vs. 4.59 [p=0.004]). As for the histologic stratification, the mean ERCC1 IRS for ADC and SqCC showed no significant difference, whereas the mean RRM1 IRS for ADC and SqCC were 3.33 and 3.94, respectively (p=0.005). In analyses according to stage at the diagnosis and response to the treatment, the mean IRS of ERCC1 and RRM1 did not show the significant difference statistically. These findings suggest that RRM1 may be more expressed in SqCC than in ADC and that despite the several previous reports, the clinical significance of ERCC and RRM1 as biomarkers in NSCLC is still controversial.