Studies suggest that the addition of antiangiogenic agents to conventional therapeutic strategies, e.g., chemotherapy, radiation, or other tumor-targeting agents, will increase clinical efficacy. For advanced colorectal cancer,the antiangiogenic agent bevacizumab has become an important treatment option and its combination with chemotherapy is now being one of the standard first line therapy. This phase II study was conducted to determine the efficacy and safety of another antiangiogenesis inhibitor rh-endostatin plus mFOLFOX6 in advanced colorectal cancer.