Abstract： Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is widely applied in non-small cell lung cancer (NSCLC).The standardized uptake value (SUV),a semi-quantitative index,plays an essential role in NSCLC for diagnosis,staging,and efficacy evaluation.It has been proposed that the SUVmax of tumors may correlate with the presence or absence of chemotherapy resistance-associated biomarkers based on studies that have displayed a close correlation between SUVmax and the expression levels of excision repair cross-complementary Group 1 (ERCC l)[1] and Tp53-induced glycolysis and apoptosis regulator.[2] FDG avidity of NSCLC and ERCC 1 and ribonucleotide reductase subunit M 1 (RRM 1)levels have not been as extensively investigated.Based on these findings,we looked for correlations among metabolic parameters (SUVmax,metabolic tumor volume [MTV],and total lesion glycolysis [TLG]) and ERCC1 and RRM1 expression in patients with NSCLC,to investigate whether FDG uptake reflects the presence or absence ofchemoresistance proteins (ERCC1 and RRM1) within tumor cells.