Apatinib is a novel drug which was produced by Jiangsu Hengrui Medicine Co.Ltd in China. It is approved in advanced gastric cancer（GC）. The investigators just want to design such kind of trail to prove its effect when combined with S-1 as maintenance in advanced HER-2 negatived GC treated with 4 cycles chemotherapy and valued as SD. Investigators will evaluate progression free survival (PFS) and overall survival (OS).

GC is the second most common cause of cancer-related deaths worldwide. Most patients are diagnosed with unresectable advanced or metastatic stage disease losing the radical surgery opportunity. Till now there is no novel targeted drug which can increase the OS for advanced GC patients except HER-2 positive patients.

Approximate 30 patients with unresectable GC treated with 4 cycles chemotherapy and valued as stable disease will be enrolled in this study,The investigators will evaluate the efficacy and security of apatinib and S-1 as maintenance therapy.

Inclusion Criteria:

1. Histologically proved advanced HER-2 negatived gastric adenocarcinoma;

2. At least a unresectable factor before operation via CT, MRI, or PET-CT: difficult resection of locally advanced gastric cancer(T4b); hepatic metastasis (H1; at most five lesions, total diameter ≤8 cm); Peritoneal metastasis(CY1, P1) ; Definitely diagnosed as unresectable GC via exploratory laparoscopy or laparotomy;

3. ECOG performance status 0-2;

4. Age≥ 18 years old, Life expectancy estimated than 3 months;

5. For results of blood routine test and biochemical tests:

   Hgb ≥ 80g/L, WBC ≥ 4000/mm3, ANC ≥ 1.5×109/L, platelets ≥ 80×109/L ALT and AST ≤ 2.5 x upper normal limit (UNL), and ≤ 5 x UNL（Hematogenous metastases）, Serum Total bilirubin ≤ 1.5 X UNL, Serum Creatine ≤ 1.5 x UNL ；

6. Good cardiac function before the recruitment, no seizure of myocardial infarction in past half years, and controllable hypertension and other coronary heart disease;

7. Not concomitant with other uncontrollable benign disease before the recruitment(e.g. the infection in the kidney, lung and liver);

8. Informed consent.

Exclusion Criteria:

1. Subjects with poor-controlled arterial hypertension (systolic blood pressure> 140 mmHg and diastolic blood pressure > 90 mm Hg) despite standard medical management;
2. Coronary heart disease greater than Class I; I-level arrhythmia (including QT interval prolongation, for man ≥ 450 ms, for woman ≥ 470 ms) together with Class I cardiac dysfunction;
3. Patients with positive urinary protein;
4. Factors that could have an effect on oral medication (such as inability to swallow, chronic diarrhea and intestinal obstruction);
5. Subjects with high gastrointestinal bleeding risk, including the following conditions: local active ulcer lesions with positive fecal occult blood test (++); history of black stool, or vomiting blood in the past 2 months;
6. Contraindications include allergy to apatinib and/or its accessories, active bleeding, intestinal perforation, intestinal obstruction, within 30 days after surgery, drugs with poor-controlled hypertension, Class Ⅲ-Ⅳ cardiac dysfunction （NYHA standard）, severe hepatic and renal dysfunction（level 4）if apatinib use is considered;
7. Abnormal Coagulation (INR>1.5, APTT>1.5 UNL), with tendency of bleed;
8. Pregnant or lactating women; Any other condition that might place the patient at undue risk or preclude a patient from completing the study;
9. Treated with 4 cycles chemotherapy included Tegafur;
10. Other conditions regimented at investigators' discretion.