An air volume adjustment device for a refrigerator comprises a fan, a baffle, an operating knob and a potentiometer. The baffle is disposed between a first air inlet cavity of a first compartment and a second air inlet cavity of a second compartment. The baffle is capable of moving among a plurality of positions to adjust the volume of air entering the first air inlet cavity and the second air inlet cavity. The operating knob and the potentiometer are connected to the front side and the rear side of the baffle respectively. The potentiometer is connected to a controller. The operating knob operably drives the baffle to move. The potentiometer transmits an electrical signal corresponding to a position of the baffle to the controller. The controller controls a rotational speed of the fan or controls the compressor to be started up or shut down.