A method and apparatus for encrypting an area of an electronic document are provided. The method includes displaying the electronic document, receiving an input signal including information about a first point and a second point of the electronic document, shifting an area adjacent to the first point toward the second point in response to the input signal, displaying only an area of the electronic document other than an encrypted area determined according to a result of the shifting, and enabling a lock mode that maintains a state of displaying the area other than the encrypted area.