The present invention relates to contrast medium composition and a method of bio imagination using the same. The contrast medium composition of the present invention includes a biomolecule, DNA nanostructure, as an active ingredient, is fundamentally non-cytotoxic and non-immunogenic and is not likely to induce safety problems that may be observed in other organic or inorganic contrast medium composition. In addition, the contrast medium composition of the present invention not only facilitates diagnosis of disease through sufficient contrast enhancement effect by showing excellent cellular uptake and intracellular stability and can visualize even SLNs which is difficult to be visualized traditionally, so can judge metastasis of cancer easily and apply lower invasive treatment.