A portable electronic device includes a housing and a display mounted onto the housing. The housing includes a bottom wall, a peripheral wall extending from the bottom wall, and a support wall extending from the peripheral wall, along a direction parallel to the bottom wall. The support wall has a top surface, and forms a receiving space together with the peripheral wall and the bottom wall cooperatively. The top surface of the support wall defines a receiving slot surrounding the receiving space. The display is mounted on the housing, and received within the receiving slot of the support wall, to align with the top surface of the support wall of the housing. The support wall further comprises a plurality of buffer slots defined in a bottom surface of the receiving slot and positioned at the corners of the housing.