This multicenter, randomized study will evaluate the efficacy and safety of apatinib compared to docetaxel treatment in patients with advanced gastric cancer. At the start of the trial, patients will be randomized to one treatment arm: Arm A: apatinib 850mg qd every 3 weeks; Arm B: docetaxel 60mg/m2 every 3 weeks. Tumor assessment will be done every 8 weeks according to RECIST 1.1. The primary endpoint is progression free survival (PFS).

Inclusion Criteria:

• Adult patients, aged ≥18 years;
• Histologically confirmed advanced or metastatic adenocarcinoma of gastric cancer(AGC) , including adenocarcinoma of the gastroesophageal junction ;
• At least one measurable and evaluable disease based on response evaluation criteria in solid tumors (RECIST v1.1);
• Patients must have received one prior chemotherapy regimen for AGC;First-line therapy must have included a combination of at least a platinum-based treatment given concurrently, and must have experienced disease progression during or after first-line therapy for their disease;
• Eastern Cooperative Oncology Group(ECOG) performance status of 0 or 1;
• Life expectancy of more than 3 months;
• Duration from the last therapy is more than 6 weeks for nitroso or mitomycin, More than 4 weeks for other cytotoxic agents, operation or radiotherapy;
• Adequate hepatic, renal, heart, and hematologic functions ( hemoglobin≥ 90g/L, platelets ≥ 80 × 109/L, neutrophil ≥1.5 × 109/L, serum creatinine≤ 1.5mg/dl, total bilirubin ≤1.5 ×ULN, and serum transaminase≤2.5×ULN);

Exclusion Criteria:

• Pregnant or lactating women;
• History of other malignancies except cured basal cell carcinoma of skin and carcinoma insitu of uterine cervix;
• Prior chemotherapy regimen have included taxane (docetaxel or paclitaxel); Uncontrolled hypertension;
• Intercurrence with one of the following: coronary artery disease, arrhythmia and heart failure;
• Urine protein>grade 1;
• Any factors that influence the usage of oral administration;
• patients with a clear tendency of gastrointestinal bleeding;
• Abnormal coagulation function(INR≥1.5, APTT≥1.5 ULN);
• Abuse of alcohol or drugs;
• Less than 4 weeks from the last clinical trial;
• Prior treatment with antivascular endothelial growth factor or the other anti angiogenesis therapy;
• Evidence of central nervous system(CNS) metastasis;
• Disability of serious uncontrolled intercurrence infection.