Patients with inoperable Non-Small-Cell Lung Cancer will receive thoracic radiation therapy 66 Gy over 33 fractions,and concurrent with 2 cycles of chemotherapy with pemetrexed (500 mg/m2,d1,repeated every 3 weeks)and carboplatin (AUC=5,d1,repeated every 3 weeks).

Inclusion Criteria:

• Histologically proven non-small cell lung cancer (non-squamous cell carcinoma)
• Presence of measurable disease by RECIST
• Inoperable stage IIIA or IIIB
• ECOG performance status 0-1
• No prior chemotherapy, radiation therapy to chest, immunotherapy, or biologic therapy
• Patients must sign an informed consent indicating that they are aware of the investigational nature of the study in keeping with the policy of the hospital.

Exclusion Criteria:

• Carcinoid tumor, small cell carcinoma of lung
• Patients with any distant metastasis
• History of another malignancy within the last five years except cured basal cell carcinoma of skin and cured carcinoma in-situ of uterine cervix Any other morbidity or situation with contraindication for chemotherapy (e.g. active infection, myocardial infarction preceding 6 months, symptomatic heart disease including unstable angina, congestive heart failure or uncontrolled arrhythmias, immunosuppressive treatment)
• Pregnant or lactating women, women who has not taken test of pregnancy (within 14 days before the first administration) and pregnant women
• Women and men of childbearing potential who have no willing of employing adequate contraception