The arbitrary waveform generator(AWG) has been developed by using GaAs field-effect transistors(FETs) and microstrip technology.The shaped electrical waveform can be adjusted.The Full-Width-Half-Maximum(FWHM) is from 0 to 3.5 ns and amplitude from 0 to 5 V.Timing precision is 200 ps.The rise time of the shaped square electrical waveform is 383 ps and the fall time is 642 ps.The top flatness of the pulse is 4~5%.The amplitude stability of the pulse is 4~5%(p-p).The AWG has been applied in the high power laser system successfully.