The present research shows the possibility of improving the factor that regulates the relative potential of the three -Phase Non-Salient-Poles Synchronous Generator by Reducing the Flux Leakage Reactance of fixed coil of the stator, at a fixed air gap and the out-put data. We proved that the flux-leakage reduction at these conditions,leads to increase the generator circumspection stability,and possibility of the coil-volume excitation reduction. This reflexes the reduction of the generator price at the same out-put data,instead of the ordinary method to rise the stability of the synchronous generator and the potential regulation-factor by the air-gap volume increase. We used the log-method to outline the relative potential regulation factor calculation depending on the practical map of the tension of the synchronous generator,considering the magnetic saturation and drawing the curves of the relative potential regulation and the stability factor by changing the leakage percentage reactance, the (S.C.R.) circuit, and the percentage change of the excitation coil cross-section(A2%),through changing the relative potential regulation .