A key assembly for an electronic device includes a key and a housing, the key being elastic and including a contact body and an assembly wall integrally formed with the contact body, the contact body has a protrusion formed thereon; and the housing has a shortened wall defining an aperture therein and a bottom wall protruding a column adjacent to the shortened wall. The key is mounted into the housing, the assembly wall is clipped to the column and the shortened wall, and the contact body abuts the shortened wall and the protrusion protrudes out of the aperture.