Abstract: A compact green laser,which can emit continuous wave or laser pulse trains respectively,was reported.With utilizing a laser diode end-pump Nd3+:YVO4+KTP gluing crystal,19% optical-optical conversion efficiency was achieved in continuous output.Adjusting the waveform of the laser power supply to gain-switch the laser diode,the corresponding output waveform of square,sine,or triangle green laser pulses were obtained.The intensity and pulsewidth of the laser pulses could be varied with the amplitude and duty circle of the injecting current pulses.Meanwhile,by changing the injecting current pulses repetition rates,the laser pulse trains repetition rates could be tuned from 0.5Hz to as high as 2MHz.A green laser pulse train,with 74ns pulsewidth,285mW peak power and amplitude noise less than 3%,was obtained at 560kHz.The research showed that green laser pulse of high repetition rates and narrow pulsewidth could be obtained by gain-switched technique.