This is an Exploratory Clinical Trial Study on Apatinib in the Treatment of Metastatic Colorectal Cancer Who Have Progressed after Standard Second Line Therapy.

Inclusion Criteria:

• ≥ 18 and ≤ 80 years of age
• Histological confirmed advanced or metastatic colorectal cancer，at least one measurable lesion, larger than 10 mm in diameter by spiral CT
• Have failed for ≥ 2 lines of chemotherapy and/or targeted therapy
• Life expectancy of more than 3 months
• ECOG performance scale 0～1
• Duration from the last therapy is more than 4 weeks for operation, radiotherapy or cytotoxic agents
• Adequate hepatic, renal, heart, and hematologic functions (platelets > 80 ×10^9/L, neutrophil > 1.5 × 10^9/L, serum creatinine ≤ 1×upper limit of normal(ULN), bilirubin < 1.5 ULN, and serum transaminase ≤ 2.0× ULN)
• Child bearing potential, a negative urine or serum pregnancy test result before initiating apatinib, must agree and commit to the use of a reliable method of birth control for the duration of the study and for 8 weeks after the last dose of test article. Male: All subjects who are not surgically sterile or postmenopausal must agree and commit to the use of a reliable method of birth control for the duration of the study and for 8 weeks after the last dose of test article.
• Signed and dated informed consent. Willingness and ability to comply with scheduled visits, treatment plans, laboratory tests, and other study procedure.

Exclusion Criteria:

• Prior VEGFR inhibitor treatment within 2 weeks
• History of other malignancies within 5 years except cured basal cell carcinoma of skin and carcinoma in-situ of uterine cervix
• Preexisting uncontrolled hypertension defined as more than 140/90 mmHg despite using single medical therapy
• More than class I (NCI CTCAE 3.0 ) myocardial ischemia, arrhythmia(including QTcF:male ≥ 450 ms, female ≥ 470 ms), or cardiac insufficiency myocardial ischemia, arrhythmia, or cardiac insufficiency
• Pregnant or lactating women
• Before or at the same time any, second malignancies except cured basal cell carcinoma of skin and carcinoma in-situ of uterine cervix
• URT: urine protein ≥ (++)and > 1.0 g of 24 h
• PT, APTT, TT, Fbg abnormal, having hemorrhagic tendency or receiving the therapy of thrombolysis or anticoagulation
• Certain possibility of gastric or intestine hemorrhage