A touch sensing method for a touch screen including an image display device with a touch-sensitive screen. The method includes a filtering process that includes calculating an output signal of an nth frame from a sensing signal of the nth frame output from a touch sensing unit configured to sense touches of the touch-sensitive screen, the calculating using an equation F(n)=I(n)×W(n)+F(n−1)×[1−W(n)], wherein F(n) represents the output signal of the nth frame, I(n) represents the sensing signal of the nth frame, F(n−1) represents an output signal of an (n−1)th frame, and W(n) represents a filtering coefficient; and outputting the output signal of the nth frame to an output end. The filtering coefficient is calculated by an equation W ⁡ ( n ) =  I ⁡ ( n ) - F ⁡ ( n - 1 )  R , wherein R is a scale constant. The touch sensing method has high touch sensitivity in an environment with heavy noise while being capable of correctly detecting touch coordinates.