 FOLFOX4 plus Avastin has been suggested as firstline regimen for advanced colorectal cancer by NCCN, a new angiogenesis inhibitor, known as EndostarRecombinant Human Endostatin, prolonged the overall survival, time to progression and improved response rate in metastatic lung cancer in a large phase III clinical trial in china, so we design this trial to evaluate the safty and efficacy of FolFox4 plus Endostar in patients with advanced colorectal cancer 