ABSTRACT: Objective To investigate the prognostic value of ERCC1 expression in patients with non-small cell lung cancer after radical surgery. Method The clinical data of 137 patients with non-small cell lung cancer who underwent lobectomy and systematic lymph node dissection in our hospital were collected. The paraffin specimens were stained with ERCC1 immunohistochemical staining and evaluated by H-score scoring standard,to analyze the correlation between ERCC1 and clinical data and the prognosis of the patients. Results H-score showed that the expression rate of ERCC1 in tumor tissues was significantly higher than that in paracancerous tissues(P<0.001). Of all the tumor tissues, 65 were positive for ERCC1(47.4%)and 72 were negative(52.6%). The positive rate of ERCC1 in squamous cell carcinoma(61.4%)was higher than that in adenocarcinoma(37.5%)(P=0.006). The positive rate of ERCC1 in smokers(62.1%)was higher than that in nonsmokers(33.8%). For patients with ERCC1 negative, the 3 years DFS(66.8%)and OS(84.6%)were better than the 3 years DFS(52.4%)and OS(64.7%)for patients with ERCC1 positive(P=0.031, P=0.012). Multivariate analysis showed that ERCC1, pathological stage, and T stage were the important prognostic factors(P<0.05). Analysis in subgroup of patients undergoing stage Ⅱ+Ⅲ systemic adjuvant chemotherapy showed that for ERCC1 negative patients, OS(73.5%)was superior to ERCC1 positive patients for 3 years and OS(56.4%)(P=0.026)for 3 years. In squamous cell carcinoma patients, ERCC1 negative patients' 3 years DFS(40.5%)and OS(69%)were better than ERCC1 positive patients' 3 years DFS(14.6%)and OS(57.1%)(P=0.041,0.045). Conclusion The expression of ERCC1 in NSCLC tumor tissue is an important prognostic factor, especially for patients with stage Ⅱ and Ⅲ undergoing systemic chemotherapy. In addition, the expression rate of ERCC1 in squamous cell carcinoma and smoking patients is higher than that in ERCC1 negative patients, and the prognosis of ERCC1 negative patients is better than that of positive patients.