Provided is a bilirubin derivative-based ultrasound contrast agent for diagnosis and treatment. The fine particles including the bilirubin derivative are sensitive to reactive oxygen species (ROS), bind with hydrophobic drugs, and can effectively chelate metals such as iron oxide nanoparticles. Therefore, the fine particle of the present invention can be used as an ultrasound contrast agent for diagnosis, as a magnetic resonance imaging contrast agent, or as a carrier for hydrophobic drugs or platinum-based drugs.