This randomized, open-label study is aimed to evaluate the efficacy of high-dose icotinib in treating advanced non-small cell lung cancer patients with positive EGFR 21 exon mutation.

Inclusion Criteria:

• Histologically or cytologically confirmed stage IIIB/IV lung cancer(exclude patients confirmed by sputum cytology)
• Positive EGFR 21 exon mutation or 19 exon deletion
• Age 18-75 years old with performance status of 0 to 2
• With a measurable disease(longest diameters >=10mm with Spiral computed tomography (CT)and >=20mm with conventional CT) according to RECIST Criteria
• Adequate hematological, biochemical and organ functions.

Exclusion Criteria:

• Severe systemic disease out of control such as unstable or uncompensated respiratory,cardiac,liver,renal diseases.
• Evidence of interstitial lung diseases
• Evidence of any other significant clinical disorder or laboratory finding that makes it undesirable for the subject to participate in the study