Multi-phase (more than three-phase) systems have attracted much attention in the recent past both for power transmission and electric drives applications. The supply from the grid is prone to unbalance and also the winding structure may have some inherent unbalance. Multi-phase systems are more sensitive to such unbalance supply conditions. Little effort has been put towards the study on the unbalance in the multiphase systems. This paper first proposes the different definitions possible of unbalance factor in five phase system to carry out the unbalance studies. Then among these definitions two suitable definitions has been selected to be used for further analysis. Where, The effect of these unbalance factors on the parameters like efficiency, power factor, and stator copper loss of a five phase induction motor has been investigated and.