NiFe2O4 microspheres were synthesized using a solvothermal method. The morphologies and structures of NiFe2O4 micropheres were characterized via a field emission scanning electron microscope（FESEM）, a transmission electron microscope（TEM） and an X-ray diffractometer（XRD）. The NiFe2O4 microspheres were around 150--200 nm in diameter and assembled by nanoparticles. The magnetic and electromagnetic parameters were measured using a vibrating sample magnetometer and a vector network analyzer, respectively. The obtained products exhibited a saturation magnetization of 60.8 A.m2·kg-1 at room temperature. A minimum reflection loss（RL） of -27.8 dB was observed at 9.2 GHz with a thickness of 3.5 mm, and the effective absorption frequency（RL〈-10 dB） ranged from 8.2 GHz to 11.2 GHz, indicating the excellent microwave absorption performance of the NiFe2O4 microspheres in the X-band frequencies.
