An computer enclosure includes a chassis having a bottom wall and a rear wall perpendicular to the bottom wall, a cover coupled to the rear wall of the chassis, two securing posts configured to extend through securing holes of the rear wall protruding from the cover, and a securing member pivotally attached to the rear wall of the chassis and capable of being rotated about a pivot axis. The securing member includes two opposite extending blocking ends for respectively engaging with the two securing posts of the cover, in which one blocking end is connected to a resilient member to provide an elastic force for urging the securing member to engage with the securing posts.