A rotary structure of a permanent magnet electric machine including a stator and a rotor is provided. The stator has K salient teeth peripherally spaced with equal intervals for forming K winding slots, wherein K is a natural number greater than 1. The rotor has an annular inner surface and has P pairs of permanent magnets peripherally spaced with equal intervals along the inner surface for rotating around the stator, wherein P is a natural number. Each permanent magnet having two sides along a peripheral direction of the rotor includes a pair of inclined surfaces on the two sides, the pair of inclined surfaces is symmetric with respect to a radial plane of the each permanent magnet, and an inclined angle α between the inclined surface and the radial plane is selected from a range of 90(1−1/(4P))