Inclusion Criteria:

- Histologically or cytologically confirmed metastatic colorectal cancer
(adenocarcinoma)

- At least one measurable lesion (RECIST criteria)

- Life expectancy ≥ 3 months

- ECOG performance status 0-2

- Adequate hematologic function: ANC ≥ 1.5×109 /L，Hb ≥ 90 g/L，PLT ≥ 100×109 /L

- Adequate renal function: Cr ≤ 1.25×ULN or Creatinine clearance ≥ 60 ml/min

- Adequate hepatic function: BIL ≤ 1.5×ULN, ALT/AST ≤ 2.5×ULN, Alkaline phosphatase ≤
5×ULN

- Patients have not previously received palliative chemotherapy, immunological/
biological treatment

- No adjuvant chemotherapy in last six months

- Target lesion has not received local radiotherapy

- Written informed consent

Exclusion Criteria:

- Diagnosis of colorectal neuroendocrine tumor, undifferentiated carcinoma,
adenosquamous carcinoma, squamous cell carcinoma

- Evidence of serious or uncontrolled infection

- Serious cardiovascular disease (congestive heart failure, uncontrollable arrhythmia,
unstable angina, myocardial infarction, serious heart valve disease, resistant
hypertension)

- Pregnant or lactating women

- Women of childbearing potential refused to practice acceptable methods of birth
control to prevent pregnancy

- Allergic to any of the study drug

- Intestinal obstruction, intestinal perforation, or stroke within 3 months

- Participation in other clinical studies