Abstract: An automatic flush sensing assembly has a driving device, a handle and a securing member. The hook end of the securing frame of the driving device is hooked onto the tank and the assembling aperture of the housing faces the assembling hole of the toilet tank. The handle is attached onto the front sleeve, the outer thread is inserted from outside the tank through the assembling hole and the assembling aperture of the housing, the signal cable of the sensor is connected to the power supply and the motor in the housing, and the rear sleeve connected to the linkage member and the control rod is inserted through the assembling aperture. The semi-circular portion of the handle is placed in the inner groove of the linkage member and the control rod is placed above the arm of the switch. Finally, the cover is placed to cover the housing.