Provided are a contrast agent for optical imaging, a use thereof and an apparatus using the same.The contrast agent for optical imaging of the present disclosure allows optical imaging without requiring a fluorophore or a luminophore. As a result, the optical images can be acquired without changing the physicochemical properties of a substrate. The contrast agent for optical imaging of the present disclosure may be used as an optical/nuclear bimodal imaging contrast agent for many applications, and allows radiation therapy as well as monitoring of a therapeutic effect thereof through optical imaging at the same time. Further, when a fluorophore is attached thereto, light emission may be enhanced without energy input from outside since light is emitted from the fluorophore, thereby increasing luminescence intensity and improving tissue penetration.