Abstract: Herein, Fe₂O₃ nanostructures were prepared by the ethylene glycol (EG) assisted hydrothermal process. The effects of the molar ratio of Fe ³⁺ and OH^-, the amount of EG, the concentration and subsequent annealing on the morphology and composition were investigated. Moreover, the effects of Fe₂O₃ nanostructures with different morphology and size on the magnetic properties were also investigated. The results indicate that only hexagonal -Fe₂O₃ nanoparticles can be obtained when the molar ratio of Fe ³⁺ and OH^-is less than 1:4 with or without the addition of EG; when the Fe ³⁺ and OH^- is more than 1:4, the orthorhombic airplane-like FeOOH nanostructures can be achieved with the assistance of EG; while the Fe ³⁺ and OH^-is more than 1:4, the orthorhombic FeOOH nanorods can be achieved without the assistance of EG. The airplane-like FeOOH nanostructures and FeOOH nanorods are transformed into the porous airplane-like Fe₂O₃ nanostructures
and Fe₂O₃ nanorods. With the increase of the concentration, only the size of the nanostructure is enlarged and the morphology of the nanostructure is unchanged. The different size and morphology have great influence on the magnetic properties of the Fe₂O_3.

Key words: ethylene glycol assisted hydrothermal process, Fe2O3 nanostructures, FeOOH nanostructures