Icotinib in Combination With Chemotherapy Versus Chemotherapy Alone in Patients Progressed After Icotinib Treatment

Inclusion Criteria: * Histologically or cytologically confirmed stage IIIB/IV lung cancer(exclude patients confirmed by sputum cytology) * 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 * N\>=1.5×109/L, Plt\>=1.0×109/L,Hb\>=10g/dL;AST\&ALT should \<3ULN(without liver metastasis) or \<5ULN(with liver metastasis).TBIL\<=1.5ULN. * 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.