A retractable frame structure of a baby stroller includes a frame, a pair of scissors-type linking sets, a push rod and a linking rod. Each scissors-type linking set is connected with the push rod and the link rod, respectively. When pushing the pushing rod, the scissors-type linking set will be collapsed and the linking rod will urge front wheels to move backward towards rear wheels, thus the collapsed stroller has a compact size which is convenient to carry and to store.