Although fist-line therapy with Cisplatin and etoposide(EP)or Carboplatin and etoposide(CE) has been given, patients with extensive small cell lung cancer(ED-SCLC) still relapse and the 2-year survival is extremely low. There is no standard maintenance treatment recommendation for ED-SCLC patients after the first-line therapy.Apatinib has been approved as a second-line treatment for advanced gastric cancer. Several phase III clinical studies of non small cell lung cancer, liver cancer, colorectal cancer and other tumors also showed apatinib has less toxic side effects and better patient tolerance. However, the clinical application of apatinib in small cell lung cancer is still lack of evidence-based medicine,so this clinical trial is designed to investigate the efficacy and safety of apatinib combine with etoposide as maintenance therapy in ED-SCLC patients after first-line chemotherapy in our center.

Inclusion Criteria:

• Histologic or cytologic diagnosis of extensive-stagesmall cell lung caner(SCLC) ,after first-line therapy
• Performance status of 0～2 on the ECOG criteria
• Expected survival is above three months
• Adequate hematologic (neutrophil count>=1.5×109/L, hemoglobin>=80g/L, platelets>=80×109/L), hepatic function (aspartate transaminase (AST) & alanine transaminase(ALT) =<upper normal limit(UNL) x2, bilirubin level =< UNL x 1.5)
• Patients have the ability to understand and voluntarily sign the informed consent, and allow adequate follow-up.

Exclusion Criteria:

• suffered from other tumor within 5 years( Except: cervical carcinoma in situ, cured basal cell carcinoma, cured bladder epithelial tumor).
• Difficulties in taking pills (inability to swallow tablets,GI tract resection, chronic bacillary diarrhea and intestinal obstruction).
• Bleeding tendency or coagulation disorders.
• Uncontrolled hypertension (systolic pressure>150 mmHg , or diastolic pressure> 90 mmHg).
• Urine protein≥++, or urine protein in 24 hours≥2.0g.
• severe uncured wounds, ulcers or fracture.
• Pregnant or breast-feeding.
• Patients with epilepsy who need to take medicine (such as steroids or anti epilepsy agents).
• The researcher believe that the Patient is not suitable to participate in the study.