Abstract: Objective ： This study was designed to investigate the effect of neoadjuvant chemotherapy followed by surgery on prognosis in patients with stage Ⅲ NSCLC. Methods ： Eight-seven patientswere randomly divided into group A (45 cases, neoadjuvant chemotherapy group) and group B(42 cases,control group without neoadjuvant chemotherapy). The patients in group A were given 1 or 2 cycles of neoadjuvant chemotherapy first, then operations were performed in 3 weeks or so after chemotherapy. Results ： The tumor response to neoadjuvant chemotherapy was 46.7% (21/45) in group A.Cox Regression told us that responding neoadjuvant chemotherapy was a protecting fact for survival (P=0.015). The 1 and 3-year survival rate and median survival time in group A and group B was 68.4%、37.2% 、20 months and 65.2%、29.8% 、18 months respectively. In group A, we got two classes according to response to chemotherapy, responding one and non-responding one, the 1 and 3-year survival rate and median survival time was 32.1%、67.8% 、21 months and 49.1%、69.1%、25 months respectively, The difference is significant (P=0.044). Conclusions ： In stage Ⅲ NSCLC patients, prognosis was better in responding patients who received neoadjuvant chemotherapy followed by surgery than those who received surgery without neoadjuvant chemotherapy. The neoadjuvant chemotherapy was harm to those who had no response to chemotherapy. We should select patients to give neoadjuvant chemotherapy according to the possibility of response.