A computed tomography contrast medium composition comprising an iodine-containing radial-shaped macromolecule, wherein the iodine-containing radial-shaped macromolecule comprises a core composed of a circular or spherical symmetric small molecular compound, or a radial-shaped macromolecule, wherein the circular or spherical symmetric small molecular compound constituting the core is any one selected from the group consisting of any one of the carbohydrates selected from the group consisting of α-, β-, and γ-cyclodextrin, glucose, galactose, mannose, porphyrin, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a cyclic peptide formed by connecting two to four peptides selected from the group consisting of lysine, aspartic acid, glutamic acid, serine, cysteine, and tyrosine, wherein the radial-shaped macromolecule constituting the core is one selected form the group consisting of any one of dendrimers selected from the group consisting of a poly(amidoamine) (PAMAM) dendrimer, a polylysine dendrimer, a poly(propylene imine dendrimer, a polyester dendrimer, a polyglutamic acid dendrimer, a polyaspartic acid dendrimer, a polyglycerol dendrimer, and a polymelamine dendrimer, any one of hyperbranched polymers selected from the group consisting of polylysine, polyester, polyglutamic acid, polyaspartic acid, and polyglycerol, any one of the star-shaped polymers selected from the group consisting of polyethylene glycol and copolymer derivatives thereof; an iodine-containing compound bound to the core directly or through a peptide wherein the iodine-containing compound is any one selected from the group consisting of the following Chemical Formulae 2, 3, 4, and 10: Wherein R 1, R 2, and R 3 are each independently or selectively -NH 2, -NHR 4, -NR 4 2, -NHNH 2, -NHNHR 4, -NHNR 4 2, -OH, - OR 4, -SH, or -SR 4, R 4 is -H, -Boc, an unsubstituted or substituted straight or branched C 1-6 alkyl or heteroalkyl, or an unsubstituted or substituted C 5-7 aryl or heteroaryl, and R 5 is the same as R 4 or -(C=O)R 4, -(C=O)OR 4, -(C=O)NHR 4, or -(C=O)NR 4 2, wherein the peptide is composed of 2 to 4 amino acid repeat units and may be selected from the group consisting of dilysine, trilysine, tetralysine, diglutamic acid, triglutamic acid, tetraglutamic acid, diaspartic acid, triaspartic acid, tetraaspartic acid, dicysteine, tricysteine, tetracysteine, diserine, triserine, and tetraserine; and a biocompatible polymer bound to the core directly or through a peptide, or directly bound to the iodine-containing compound bound to the core, wherein the biocompatible polymer is any one selected from the group consisting of polyethylene glycol, hyaluronic acid, heparin, wherein the iodine-containing radial-shaped macromolecule has a structure in which the biocompatible polymers form a protective layer to prevent the exposure of the core and the iodine-containing compound in vivo, wherein the iodine content of the iodine-containing radial-shaped macromolecule is in the range of 15% to 50%. Wherein R 1, R 2, and R 3 are each independently or selectively -NH 2, -NHR 4, -NR 4 2, -NHNH 2, -NHNHR 4, -NHNR 4 2, -OH, - OR 4, -SH, or -SR 4, R 4 is -H, -Boc, an unsubstituted or substituted straight or branched C 1-6 alkyl or heteroalkyl, or an unsubstituted or substituted C 5-7 aryl or heteroaryl, and R 5 is the same as R 4 or -(C=O)R 4, -(C=O)OR 4, -(C=O)NHR 4, or -(C=O)NR 4 2, wherein the peptide is composed of 2 to 4 amino acid repeat units and may be selected from the group consisting of dilysine, trilysine, tetralysine, diglutamic acid, triglutamic acid, tetraglutamic acid, diaspartic acid, triaspartic acid, tetraaspartic acid, dicysteine, tricysteine, tetracysteine, diserine, triserine, and tetraserine; and a biocompatible polymer bound to the core directly or through a peptide, or directly bound to the iodine-containing compound bound to the core, wherein the biocompatible polymer is any one selected from the group consisting of polyethylene glycol, hyaluronic acid, heparin, wherein the iodine-containing radial-shaped macromolecule has a structure in which the biocompatible polymers form a protective layer to prevent the exposure of the core and the iodine-containing compound in vivo, wherein the iodine content of the iodine-containing radial-shaped macromolecule is in the range of 15% to 50%.