• Male or female, aged at least 18 years, younger than 75 years.

• Histologically confirmed diagnosis of primary non-small lung cancer (NSCLC) on predominantly non-squamous histology.

• Before surgery or randomization, MRI or CT scan of the brain and bone scan must be done to exclude metastases.

• Complete resection (R0) and systematic lymphadenectomy are mandatory: all surgical margins must be negative for tumor, and there should be no extranodal invasion of the mediastinal lymph nodes or marginal lymph nodes.

• Patients with postoperative pathological confirmation of stage II, IIIA and IIIB (only T3N2M0) are eligible.

• Patients must harbor one of the two common sensitizing EGFR mutations (Ex19del, L858R), either alone or in combination with other EGFR mutations including T790M, the mutations should be confirmed by the central laboratory.

• Complete recovery from surgery and standard post-operative therapy (if applicable) at the time of randomization.

• A ECOG performance status equal to 0-1 with a minimum life expectancy of 12 weeks and no deterioration over the past 2 weeks.

• Adequate bone marrow reserve or organ function, as demonstrated by the following laboratory values (no corrective treatment allowed within one week before blood sampling):

‣ Absolute neutrophil count (ANC）≥1.5×10\^9 /L

⁃ Platelet count ≥100×10\^9 /L

⁃ Hemoglobin ≥90 g/L

⁃ Alanine aminotransferase (ALT) ≤ 2.5 × upper limit of normal (ULN) if no demonstrable liver metastases or ≤ 5 × ULN in the presence of liver metastases

⁃ Aspartate aminotransferase (AST) ≤ 2.5 × ULN if no demonstrable liver metastases or ≤ 5 × ULN in the presence of liver metastases

⁃ Total bilirubin (TBL) ≤ 1.5 × ULN if no liver metastases or ≤ 3 × ULN in the presence of documented Gilbert's Syndrome (unconjugated hyperbilirubinemia) or liver metastases

⁃ Creatinine ≤ 1.5 × ULN concurrent with creatinine clearance ≥ 50 mL/min (measured or calculated by the Cockcroft-Gault equation); confirmation of creatinine clearance is only required when creatinine is ≤ 1.5×ULN

⁃ Serum albumin (ALB) ≥28 g/L

⁃ Coagulation function: International standardized ratio (INR) ≤1.5, activated partial thromboplastin time (APTT) ≤1.5×ULN

• Females of child-bearing potential should be using adequate contraceptive measures throughout the study, should not be breast feeding during the study and until 6 months after treatment, and must have a negative pregnancy test prior to start of dosing.

• Male patients should be willing to use barrier contraception during the study and until 6 months after treatment.

• Patients must sign and date written informed consent prior to admission to the study.