Magnetic nanoparticles are widely used in magnetic fluid, magnetic grinding materials, magnetic controllers, magnetic sensors, biomedicine fields and so on. Recently, more and more attentions were focused upon DDS (Drug Delivery System). In this study, Magnetite nanoparticles about 8nm size were synthesized by liquid phase precipitation method. Then the nanoparticles coated with surfactant were dispersed throughout kerosene and inject the solutions into biomaterials. Using strong photon beams in SPring-8 facility, we observed the distribution state and the effect of magnetic field on the behaviour of nanoparticles in biomaterials.