A wireless sensing device includes a wireless transmitter module, a microprocessor unit, and a wake-on unit. When the wireless transmitter module receives a sensing signal from outside and transmits it to the microprocessor unit, the microprocessor unit may enter a hibernation mode or a sleep mode form its previous on-duty mode depending on the level of the sensing signal. When the wireless transmitter module receives a wake-on signal from outside and transmits it to the wake-on unit, the wake-on unit generates a resume-from-hibernation command or a resumefrom-sleep command for the microprocessor unit depending on the level of the wake-on signal so as to resume the microprocessor unit.Most battery-driven wireless sensor devices will enter sleep mode as soon as possible to extend the overall lifetime of a sensor network. It is necessary to turn off unnecessary radio and peripheral functions, especially the radio unit always consumes more energy than other components during wireless communication. The microcontroller always has different sleep modes, each with a different level of energy usage. Most wireless sensor devices have the external low-frequency oscillator to wake up the sleeping microcontroller when the sleep timer expires. However, our sensor device can enter the extended sleep mode: none of the oscillator is running and the wireless sensor device has the nanoampere consumption and self-awaking ability.Our ultra-low power saving technology is used for battery-driven wireless sensing device that has the nanoampere consumption and self-awaking ability. Ultra-low power consumption technology can be applied to home security system, parking management system, smart campus management system, smart factory, smart agriculture, and smart aquaculture.