A simple over-temperature protection circuit with low power consumption is designed for power management ICs(integrated circuits)．With 0.6 m BCD technology，Hspice simulation shows that the circuit has high sensitivity to temperature and low power consumption，the errors of shutdown temperature are less than 0.7 ℃ when the shutdown temperature is set at 150 ℃ and the voltage of power source is 2.5 to 5.5 V，and the errors of reswitch-on temperature are less than 0.9 ℃ when the reswitch-on temperature is set at 130 ℃.