In this paper,single-phase and fine-grain hexagonal barium ferrite powder was prepared based on the optimal calcination condition.The influence of calcination conditions including temperature and holding time on microstructure and magnetic properties of powder were studied in detail.Firstly,θ-2θ scan X-ray diffraction (XRD) results reveal that it is hard to obtain single phase of powder when the calcination temperature is lower than 850 ℃.In addition,the calcination time for single phase of barium ferrite powder was reduced with the increase in calcination temperature.Scanning electron microscopy (SEM) images and magnetic hysteresis loops show that the condition of low temperature and long holding time is beneficial for obtaining homogeneous size of grain and excellent magnetic properties.Consequently,hexagonal barium ferrite powder with uniform grain size of ～ 180 nm,high purity and excellent magnetic properties is obtained at optimal calcination condition of 850 ℃-10.0 h.