A portable supporting apparatus for a portable multimedia device includes a support housing and a mounting arrangement. The support housing includes a multimedia connector for detachably connecting with the portable multimedia device. The mounting arrangement is provided underneath the support housing, and includes a plurality of supporting legs, each having a predetermined shape, pivotally and downwardly extended from the support housing, wherein supporting legs are adapted to move between an idle position, and a mounting position where each of the supporting legs is pivotally moved to form a predetermined angle of inclination with respect to the support housing so as to bias against an external object for frictionally retaining a position of the support housing with respect to the external object, such that the portable multimedia device is capable of being securely supported by the external object through the portable supporting apparatus.