The aim of this work is to study the design and construction of an Nd:YAG laser system to produce a tunable repetition rate in a laboratory scale. Electronic circuits and the resonator were both built to achieve lasing action of TEM00 mode, passive Q- switched and tunable repetition rate, this work also includes the construction of the cooling system which consists of heat exchanger and water pump. Laser peak power was measured to be 10 MW, with a pulse width of 10 ns and a tunable repletion rate between (0.5 - 10) Hz by steps of 0.5 Hz.