A carrier adjusting mechanism is applied to a stroller including a stroller frame and a carrier and includes a base, a locking structure, a locking device, and a release actuator. The base is connected to the stroller frame. The locking structure is connected to the carrier and pivoted to the base. The locking device is disposed between the base and the locking structure. The locking device includes a first engaging structure, a second engaging structure, and a locking member. The locking member is engaged with the first engaging structure at a first position or the second engaging structure at the second position. The release actuator is disposed on the stroller and connected to the locking device for disengaging the locking member from the first engaging structure or the second engaging structure, to allow the locking structure to move between the first position and the second position together with the carrier.