The preparation of spinel ferrite nanocrystals through different routes has become an essential in research and development. But, the most commonly applied synthesis methods are difficult to employ on a large scale because of their complicated procedures, high reaction temperatures, long reaction times, toxic reagents and by-products, and their potential harm to the environment. In this thesis a simple thermal treatment method is described for synthesis of spinel ferrite MFe2O4 (M = Ni, Co, Mn, Zn, or their binary metal) nanoparticles. In this method, an aqueous solution of poly (vinyl pyrrolidone) (PVP) was prepared by dissolving the polymer in deionized water at 343 K before adding iron nitrate and respective metal nitrates and constantly stirring at 353 K for 2 h.