The R Zn ferrite, which has low Curie temperature was prepared. The samples were tested by XRD, the hysteresis loop, thermal mass loss analysis and thermomagnetic test. The results showed that R Zn ferrites have low Curie temperatures, which tend to be lower with the increase of the content of Zn in the specimens. Moreover, those specimens have typical hysteresis loop of ferrite materials. Being placed under the alternative magnetic field, the samples have the obvious thermomagnetic effect.