Abstract: MnZn ferrite with low power loss and high Bs at high operating temperature has been prepared by choosing highly pure raw materials, using conventional ceramic process，and adding optimum contents of CaCO3, TiO2, Nb2O5, and V2O5. According to the solid-phase reaction mechanism of ferrite，optimum sintering process and matched atmosphere were used to prepare high quality MnZn ferrite material. High density, high Tc and high Bs were achieved.

Key words: dpoants, low power loss, sintering process, MnZn ferrite