Abstract: The laser ions always synchronous to the high repetitive laser pulse and appear in fixed period of time in experiments of laser resonance ionization. A high efficiency synchronous gate-selected counter was accomplished by using of modularized preamplifier/discriminator, universal counter, self-designed analog switch and synchronous circuit. The pulses come from electro magnetic interference of the lasers, which are not in the select gate, which are excluded. The count of random pulse arise from the ion-source, SEM (Second Electron Multiplier) and preamplifier are reduced in proportion to the duty cycle of the select gate.