A touch screen of a mobile terminal and a power saving method thereof are provided. The power saving method of a touch screen for a mobile terminal includes determining whether a touch panel is contacted by controlling light emitting elements to emit light with a first scan speed and detecting whether light is received by light receiving elements; and decreasing, if the touch panel is determined not to be contacted for a predetermined time duration, a scan speed from the first scan speed to a second scan speed after lapse of the predetermined time duration. Therefore, if a contact occurs within the predetermined time duration, the contact is detected by executing the scan with the first scan speed, and if no contact is detected before lapse of the predetermined time duration, the scan speed is decreased, whereby electric current waste due to the scan can be minimized.