The invention discloses an automatic reset detection circuit for power up and power failure. The circuit comprises a power supply detection circuit (1), a band-gap reference circuit (2), a voltage comparator (3), a ring-shaped RC (remote control) oscillator (4) and an M-bit counter (5), wherein the power supply detection circuit (1) is used for detecting change of power supply voltage, when the power supply voltage is higher than preset threshold voltage, the voltage comparator (3) outputs a high voltage level, the ring-shaped RC oscillator (4) and the M-bit counter (5) begin to work, after 2M periods, an output Reset signal is changed to the high voltage level, and the power up reset detection is completed; when the power supply voltage is lower than the preset threshold voltage, the voltage comparator (3) outputs a low voltage level, the ring-shaped RC oscillator (4) and the M-bit counter (5) stop working, the output Reset signal is changed to the low voltage level, and the power failure reset detection is completed. The automatic reset detection circuit is simple in structure and easy to implement, and further has the power up and power failure reset detection functions simultaneously.