Condition monitoring of operating equipments with diagnosis of faults in incipient stages and preventing of failure leads to very less repair cost, less damage due to shut down, and increase in reliability, that specially in expensive and vital applications is very important. On the other hand, favorite characteristics of induction motors cause to it contain majority use. Stator faults consist of winding and core faults, that usually start from inter-turn short circuits, in second place, contain 30-40 % of all electrical machine faults. There are several methods for detecting this fault, but main problem of these methods is sensitivity to nonideal conditions such as supply voltage unbalance. Among these is motor current signature analysis that due to its noninvasive and easy implementation has very usage. Motor current spectrum analysis in stator winding fault condition leads to this result that rotor slot harmonics are increased. But these harmonics have the same response to unbalanced supply voltage. In this project, early purpose is current spectrum analysis in faulty condition that the reason of rotor slot harmonics is specified. Then research for the same effect of supply voltage unbalance on them, that the difference of short circuit from this condition is determined. And the final purpose is developing a method that able to detect inter-turn short circuit in voltage unbalance condition. Therefore, in early very some stator winding fault diagnosis methods are introduced. Fault indicator, characteristics and problems are presented and then the methods are evaluated. So for modeling of the induction motor in faulty condition, machine equations consist of rotor and stator voltage, mechanical, and short circuited coil equation are developed. Also winding function approach for calculating of the inductances is used. Then for analyzing of the motor current spectrum, rotor and stator space harmonics of magnetomotive force are introduced and with simulation results, the spectrum of motor current in healthy and faulty conditions is analyzed. Rotor slot harmonics are introduced and are showed that the magnitude of some of them increase in faulty and unbalanced voltage condition. In continue a new method for stator wing fault diagnosis in unbalanced supply voltage condition based on three phase current spectrum analysis is proposed. In the end, after describing of prepared setup, experimental results are presented. Experiments are done in no load and load condition, healthy and tow short circuit mode, and three value of voltage unbalance factor, totally 18 experiments. The results Keywords: Induction Motor, Stator Winding Turn Fault, Fault Diagnosis, Condition monitoring, Motor Current Signature Analysis (MCSA), Unbalanced Supply Voltage