Metallofullerene monocrystalline nanoparticles are used as tumor vascular disrupting agents. The monocrystalline nanoparticles are water-soluble metallofullerene nanoparticles with negative charges on their surfaces. The particle sizes range from 50 to 250 nanometers. The nanomaterials are able to absorb outside radiation energy, and transform it into heat energy. The volumes rapidly expand when temperature reaches a phase transformation point. For treatment, metallofullerene monocrystalline nanoparticles are administrated to a tumor-bearing organism via injection. The metallofullerene monocrystalline nanoparticles reach tumor sites via blood circulation, and are retained at the tumor sites. The monocrystalline nanoparticles of metallofullerene accumulate heat and the temperature increases under outside radiation energy. The volumes sharply expand when the temperature exceeds a critical point of phase transition thereof, thereby causing changes in the morphologies, structures or functions of endothelium cells of tumor vessels.
