 Angiogenesis, the formation of new blood vessel from existing vessels, is essential for tumor growth and metastasis. Antiangiogenic therapies inhibit the growth of genetically stable endothelial cells, and most tumors should starve to death with little acquired resistance. Endostatin has been shown to block endothelial cell proliferation, survival, and migration. Antitumor activity of endostatin protein has been demonstrated in various murine and human tumors in animal model studies without any detectable toxicity. Endostatin gene therapy could directly express the highly bioactive protein in vivo by means of the mechanism of eukaryotic expression system as post-translational modification and folding, as well as overcoming the challenge of the long-term storage and the cumbersome daily administration of endostatin protein. 