Magnetic nano particles, how to make magnetic Fe3O4 by precipitation using ammonium hydroxide, MNP. In area of magnetic nanoparticles for drug delivery, magnetic nanoparticles review, magnetic nanoparticles synthesis, magnetic nanoparticles applications, magnetic nanoparticles for cancer therapy How to make Iron Oxide magnetite Nanoparticles ? By this method Magnetite Fe3O4 nano particles obtained narrow size distribution about 40 nm. It can be used many area such as hyperthermia, MR imaging.