Rare earth permanent magnet and a preparation method

The present invention relates to a rare earth permanent magnet and a preparation method. In particular, coated with a sintered magnet body (RaT1bMcBd) powdered intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or a metal (M1) and the rare earth powder (R2) of a mixture of oxides diffusion treatment. R2 oxide is reduced in the portion of the diffusion process, so that a large number of grain boundaries in the form of the R2 channel by the introduction vicinity of the interface in main phase inside the magnet. In so while minimizing a decline of remanence, coercivity is improved.