After the August 14, 2003 blackout, power system stability probelm has received a great deal of attention. This project is focused on the analysis of transient stability following disturbances. The project investigates three generator-excitation techniques for controlling the stability of power system. They are the manual control (constant excitation voltage), the automatic voltage regulator (AVR), and the automatic voltage regulator plus the power system stabilizer (PSS) that basically can be a led-leg compensator using a rotor speed deviation as an input feedback. This project carried out a computer simulation study of the power system stability for various disturbances conditions. The simulation results from the project have shown that AVR coupled PSS generator-excitation control can achieve the best power system stability, comparing to the manual or AVR control. A major contribution of this project is that a computer platform using MatLab/Simulink software was designed and can be used by other researchers for the power system stability study.