Abstract: Abstract：Objective To investigate the inhibitive effect of antisense VEGF165 cDNA on growth and angiogensis of human neuroblastoma in nude mouse models. Methods Three kinds of SH-SY5Y cells which had been stably transfected by sense VEGF165 cDNA, antisense VEGF165 cDNA and empty vector respectively, were inoculated subcutaneously to nude mice. The size of subcutaneous tumors was measured, and the morphology of tumor tissue was observed by microscope. The microvessel density (MVD) in tumor mass was analyzed by CD31 immunohistochemistry staining. Apoptotic cells were detected by the electron microscope. Results The growth of tumor mass, which was inoculated with antisense VEGF, decreased significantly in nude mice compared with empty vector group (P＜0.05), while the growth rate oftumor in the sense VEGF group increased significantly in nude mice (P＜0.05). The morphologic investigation of SH-SY5Y cells in antisense group showed blood vessel sparsity, smaller nuclei, fewer cytoplasm, lesser mitotic figure compared with the empty vector group. The electron micrographs of SH-SY5Y cells in antisense group showed the characteristics of apoptosis: the chromatin condensed in masses at the periphery of nuclei, and the nuclear fragmentation were seen, but they were not seen in sense group and empty vector group. MVD in rumor mass of the antisense group decreased significantly compared with empty vector (P＜0.01), and MVD of sense group increased significantly (P＜0.01). Conclusions Antisense VEGF165 cDNA transfection could inhibit the proliferation of SH-SY5Y cells in the nude mice, decrease angiogensis and increase tumor cells apoptosis.