A foldable mechanism is applied to locking an infant carrier and includes first and second mounts and a locking member. The second mount is pivoted to the first mount and has first and second mating portions. The locking member is movably disposed between the first and second mounts and is movable along an axial direction of a rotating axis of the first and second mounts to lock and release rotation of the first mount. The locking member has a positioning portion and a locking portion. The first mount is locked at a first rotating position or a second rotating position via movement of the locking member. The positioning portion is engaged with the first mating portion to lock the first mount at the first rotating position. The locking portion is engaged with the second mating portion to lock the first mount at the second rotating position.