Child safety seat assembly

A child safety seat assembly includes a support structure (104) having an upper surface provided with an opening (142), and a child carrier (102) operable to detachably assemble with the support structure, the child carrier including a seat shell having an outer surface facing downward, and the seat shell being pivotally assembled with a latch (124). The latch has a stem protruding downward from the outer surface, and a radial projection connected with the stem. The latch is insertable into the opening to lock the child carrier with the support structure.