A capacitive touch system including a drive end, a capacitive touch sensing device and a detection end is provided. The drive end inputs a modulated drive signal into an input channel of the capacitive sensing device, wherein the modulated drive signal includes a plurality of driving frequencies. The detection end detects a detection signal of an output channel of the capacitive sensing device and generates a two-dimensional detection vector corresponding to each of the driving frequencies. The capacitive touch system includes a touch panel or a touch keyboard.