We hypothesize that higher dose icotinib is related with better efficacy. The primary objective is to compare the progression-free survival of higher dose and routine dose of icotinib in treating pretreated advanced non-small cell lung cancer patients with stable disease after 8-week routine dose icotinib treatment.

Inclusion Criteria:

• Histologically or cytologically confirmed stage IIIB/IV lung cancer(exclude patients confirmed by sputum cytology);
• Pretreated with at least 1 platinum-based chemotherapy;
• No previous targeted treatment such as gefitinib, erlotinib;
• With a measurable disease(longest diameters >=10mm with Spiral computed tomography (CT)and >=20mm with conventional CT) according to RECIST Criteria;
• WHO performance status(PS)<= 2;
• Adequate organ functions;
• Signed and dated informed consent before the start of specific protocol procedures.

Exclusion Criteria:

• Allergic to icotinib;
• Patients with metastatic brain tumors with symptoms;
• Experience of Anti-EGFR(the epidermal growth factor receptor) Monoclonal Antibody or small molecular compounds therapy such as gefitinib, erlotinib or Cetuximab;
• Severe systemic disease out of control such as unstable or uncompensated respiratory,cardiac,liver,renal diseases.