A handheld electronic device comprises a shiftable pivot structure (230) interconnecting a flip cover (210) to a base (220) of the device. The base has a pivotal accommodation groove (224) and the flip cover has a pivot sleeve (212). The shiftable pivot structure comprises a sliding axle (240) slideably fitted in the pivotal accommodation groove. The shiftable pivot structure is hinged to the pivot sleeve. When the flip cover is closed, the pivot sleeve of the flip cover can be moved to be hidden within the pivotal accommodation groove to get protection and to keep the appearance of the device neat. For communication, the flip cover needs to be opened, which is accomplished by firstly shifting the pivot sleeve and the sliding axle outwardly to a position in which the pivot sleeve protrudes from the pivotal accommodation groove, and then pivoting the flip cover relative to the base to an open position.