Abstract: ObjectiveTo evaluate and analyze the prognostic factors of locally advanced non-small cell lung cancer (LANSCLC) with involved-field three dimensional conformal radiotherapy (3D-CRT). Methods One hundred and fifteen patients with NSCLC treated with involved-field 3D-CRT between March 2004 and December 2007 were analyzed and evaluated retrospectively. The PTV given dose was over 50 Gy, with 1.8～2.0 Gy per fraction, 1 time a day, 5 fractions a week. There were 42 and 73 patients received radiotherapy alone and chemoradiotherapy respectively. The volume of GTV was calculated on TPS. The impact of related prognostic factors on survival was evaluated by univariate and multivariate analysis. ResultsThe 1, 2 and 3-year survival rates were 63.4%, 33.8% and 18.0%, respectively, and the median survival time was 17 months. Female, Smaller GTV and sufficient chemotherapy were favorable factors for survival in univariate and multivariate analysis (P=0.027, 0.000, 0.002 and P=0.037, 0.029, 0.008, respectively). ConclusionFemale, smaller GTV volume and optional chemotherapy are favorable prognostic factors for NSCLC. Involved-field 3D-CRT confers no increasing elective nodal failure.