The present invention relates to DTPA derivatives capable of forming complexes by combining with metals and the like, metal complexes formed by combining with the DTPA derivatives, MR and CT contrast agents including gold (Au) nano-particles of which surfaces are coated with the metal complexes, and a method for manufacturing the same. The MR and CT contrast agents according to the present invention have a high magnetic relaxation rate, thereby providing an excellent contrast enforcement effect and a long image acquisition time. Furthermore, the MR and CT contrast agents are not toxic to the human body, and are image contrast agents of dual molecules capable of being applied to both MR and CT.