Abstract: In order to improve the utilization ratio of permanent magnet assisted switched reluctance motor(PMA-SRM), a series magnetic circuit PMA-SRM(SPMA-SRM) is proposed. The stator is composed of six U-shaped modules, and PMs are located at the slot openings between each two adjacent U-shaped modules. PMs are tangentially magnetized and the direction of magnetization is the same. When the motor is unloaded, the PM field forms a series magnetic circuit in the U-shaped stator core, which is not coupled with the rotor. When any phase winding is energized, all PMs work at the same time due to the special series magnetic circuit design. So, the utilization ratio of PM is improved. The topological structure and working principle of SPMA-SRM and the existing parallel magnetic circuit PMA-SRM are introduced, and the dimension parameters are designed. By the finite element method, the electromagnetic performances of two motors are analyzed and compared. A SPMA-SRM prototype is manufactured and the performance of the motor is tested experimentally. The research results show that the utilization ratio of PM of the SPMA-SRM is 200% higher than that of the parallel magnetic circuit PMA-SRM in condition of the same output performances.