A tilting portable electronic device includes a main body, a cover having a sliding plate, a sliding mechanism connecting to the main body and the cover respectively. The sliding mechanism includes a first plate secured to the main body, a second plate slidably engaging with the first plate, two connecting bars and two swing arms. The connecting bars rotatably connect with the second plate and the sliding plate, the swing arms rotatably connect with the main body and the connecting bar. When the sliding plate is pushed and slides relative to the main body, the connecting bars slides, the first plate correspondingly slides relative to the second plate, and the swing arms rotates to support an end of the cover.