Abstract: Multi phase motor can be designed as a composition of a certain number of three phase winding. The analysis on magnetomotive force of the multi phase motor winding can be greatly simplified if the three phase winding is used as a separate unit. A general expression of phase difference is presented by analyzing the respective magenetomotive force from two sets of the three phase winding. A new method of the space vector method is presented to make the magnetomotive force analysis of the multi phase motor easy and applicable. The twelve phase motor is presented as an example to support the advantages of the space vector method. The space vector method can be utilized to design the winding of multi phase motor to eliminate a certain harmonic magnetomotive force.