Generally, the surgical resection has been considered to be the standard therapy for the clinical Stage I-IIIA non-small cell lung cancer (NSCLC). However, the 5 year-survival rate has been reached approximately less than 20%. To improve the prognosis, especially for the Stage IIIA NSCLC, many clinical trials have been performed to assess the availability of the chemotherapy or radiation therapy in the preoperative or postoperative period. Although some clinical trials concerning about the neo-adjuvant therapy have reported the improvement of the postoperative survival rate, the availability of both neo-adjuvant and adjuvant therapy is still controversial. Further assessment for the well designed phase III clinical trials will be necessary to establish the availability of such modalities for the treatment of respectable NSCLC.