Abstract: Objective To explore the clinical significance of the expression levels of excision repair cross-complementation group 1(ERCC1) and ribonucleotide reductase M1(RRM1) in non-small cell carcinoma(NSCLC). Methods Total 43 patients with NSCLC in our hospital from August 20,2013 to October 20,2014 were enrolled into this research.The expressions of ERCC1 and RRM1 were detected by RT-PCR.The positive expressions of ERCC1 and RRM1 in NSCLC tissue and tumor adjacent tissue,and low,middle,high differentiation of cancer tissues were compared.The relationship between the positive expression of ERCC1 and RRM1 was analyzed. Results The results of Rt-PCR detection show that the positive expressions of ERCC1 and RRM1 in NSCLS tissue (81.40%,69.76%) were obviously higher than those in tumor adjacent tissue(39.53%,25.58%),P<0.05.The expression of ERCC1 was positive in 35 patients,and the positive expressions in high differentiation of cancer tissues were higher than those in low,middle differentiation(P<0.05),but had no significant difference in squamous cell carcinoma,large cell undifferentiated carcinoma and adenocarcinoma(P>0.05).The expression of RRM1 was positive in 30 patients,and the positive expressions in low differentiation of cancer tissues were higher than those in middle,high differentiation(P<0.05),but had no significant difference in squamous cell carcinoma,large cell undifferentiated carcinoma and adenocarcinoma(P>0.05).The positive expression of ERCC1 and RRM1 had a positive correlation(correlation coefficient r=0.841,P<0.05). Conclusion The expression of ERCC1 and RRM1 in cancer tissues is more active,and there is a positive correlation between ERCC1 and RRM1 with a changed expression rate in the tissues with different degrees of differentiation.The positive expression of both is not related with the cancer types.