In this thesis, a heat system of rectangular ring is design and analyzed. It contains a rotating magnetic inner ring and fluid. Some rotating magnetic field can derive the magnetic ring to rotate. Due to non-contact design, there is no leakage problem of the conventional design. Moreover, it is helpful for disturbing the fluid and heat transferring. This is an innovative design. The flow field and heat transfer of this system are analyzed by using the commercial software, STAR-CD. The effects of several parameters on the heat transfer are investigated. The optimum parameters for heat transfer are found.