The present invention relates to an adenovirus complex which can be utilized for gene delivery and gene therapy by targeting neurotensin receptors. The complex of the present invention has an excellent antitumor effect because of a high intracellular gene transfer efficiency and target specificity by neurotensin receptor-specific binding, has little hepatotoxicity and immunogenicity, forms a stable complex, has low immunogenicity, and thus has a low loss in blood even in an in vivo environment. Therefore, the complex of the present invention can be effectively used for gene therapy.