This book gives brief review for stability improvement using Fuzzy and GA techniques. and has essentially investigated on the change in frequency as well as change in the tie line power due to the change in the load and also the techniques that may be used for obtaining the optimized values of various parameters for minimizing the changes. The existence of low-frequency oscillations in power systems is the cause of power angle instability, limiting the transmission of maximum tie-line power. One of the effective ways to improve the stability limits is by installing a power system stabilizer and supplementary excitation control to augment with an automatic voltage regulator (AVR) supplemental feedback stabilizing signal. The investigation of the enhancement of the power system steadiness by the coordinated application of numerous damping controllers is thoroughly achieved. A time-domain objective function is utilized to diminish the oscillations of the power system for the controller design problem that has been proposed.