A multi child stroller includes a stroller frame and a first seat. The stroller frame has two sections adapted to fold and unfold relative to each other. The first seat is disposed on one of the two sections. The first seat includes a first seat unit and a seat back positioning member. The first seat unit has a sliding slot portion. The seat back positioning member is rotatably disposed on the stroller frame. The seat back positioning member includes a sliding bar adapted to slide inside the sliding slot portion, so as to switch the first seat unit into one of a first unfolding mode, a second unfolding mode and a folding mode.