An apparatus and method for turning pages of an electronic-book (e-book) in a portable terminal having an e-book function. The method includes executing the e-book function, displaying a right lateral side of the e-book and receiving a inclination value from a 3-axis sensor when a touch event is detected in a right User Interface (UI) active area of the e-book, determining whether the inclination value greater than or equal to a threshold is detected in a left direction, and upon detection of the inclination value greater than or equal to the threshold in the left direction, displaying a next page to a screen on a single-page basis at a speed in proportion to the inclination value detected in the process of detecting the inclination greater than or equal to the threshold in the left direction.