A preferred embodiment of the touch sensing apparatus includes one or more touch sensing units, a detector, and a signal processing unit. Each touch sensing unit comprises: a differential signal source for generating two signals which have a same frequency but reverse phases; and two sensors for receiving a touch signal of a user's finger. One sensor is connected to an anode of the differential signal source, and the other sensor is connected to a cathode of the differential signal source. The detector is for converting the received signal into a digital signal. An input terminal of the detector is connected to the sensors of each touch sensing unit. The signal processing unit is for determining which sensor is touched according to the frequency and phase of the signal output from the detector. The signal processing unit is connected to an output terminal of the detector. The touch sensing unit may further include a reference signal circuit.