Diode end-pumped the Brewster cut Q-switched Nd:YVO4 master oscillator and power amplifier(MOPA) of Nd:YAG laser with high energy,narrow pulse width output has been developed.The single pulse energy of master oscillator is 0.16 mJ at 5 Hz,and the pulse width is 0.964 ns.In order to avoid the ASE effect of the Nd:YAG amplifier,the isolator and the 1.5 degree cut Nd:YAG crystal are adopted.After Nd:YAG double pass preamplifier,the single pulse energy of 88 mJ and the pulse width of 0.972 ns are achieved.After Nd:YAG single pass post amplifier,the single pulse energy of 3.25 J,pulse width of 1.051 ns and M2=1.9 are acquired.The unstable degree of laser output is less than