This paper presents several kinds of Interior Permanent Synchronous Motors (IPM) used for high power density and high speed application. The main permanent magnet arranged forms and pole/slot match manners includes 72 slots 12 poles (72s12p) V-shape and 72 slots 8 poles (72s8p) ▽-shape. In addition, several different 72s8p ▽-shape motor will be discussed in detail. For analyzing the machines under rotating magnetic fields, field-circuit couple, half-symmetric boundary and slide boundary are considered.