A child carrier apparatus having at least two configurations of use. In some embodiments, the child carrier apparatus comprises a support frame, a seat assembly mounted on the support frame and including a front seat frame and a rear seat frame operable to rotate about a pivot axle relative to the front seat frame, and a lock mechanism including a locking element assembled with the rear seat frame and operable to move relative to the rear seat frame between a first and second position. The locking element when in the first position is configured to engage with a portion of the front seat frame for locking the front seat frame with the rear seat frame. In some embodiments, a method of operating the child carrier apparatus is also described.