Myanmar has very rich hydropower resources with a total potential of around 100,000 MW. For obtaining efficient stability and good regulation of generator exciter control in hydropower system, automatic voltage regulators (AVR) are increasingly used.This paperpresents the modeling and control of the excitation system with the automatic voltage regulator (AVR) to improve stability on a micro hydro power plant. The objective is to consider a generator AVR system without stabilizer and PID controller and with stabilizer and PID controller. The PID controller automated tuning was used with a view for improving the response of the system and make comparison between the frequency deviation step response. The transfer function controller blocks use linear block model and control techniques in MATLAB/ Simulink environment.