Controllable preparation of nanomaterials with various sizes and shapes has always been the key research in the field of material preparation due to different application requirements.To further study the effect of sizes and shapes of CoFe2O4 nanoparticles on its magnetic properties,CoFe2O4 nanoparticles with different sizes and shapes were prepared by the conventional liquid phase method and the"seed-growth"liquid phase method in this paper,and the magnetic properties were studied.As a result,the change of sizes and shapes for CoFe2O4 nanoparticles can influence the dispersion and coercivity of nanoparticles.Among them,the coercivity of the hexagonal CoFe2O4 nanoparticles prepared by the"seed-growth"liquid phase method can reach 383 Oe at room temperature and as high as 13105 Oe at 80 K.