An apparatus for leaving a message on a refrigerator is disclosed. The apparatus can be mounted on the refrigerator so as to broadcast a voice upon opening a door of the refrigerator. A control unit for processing and controlling the voice is mounted on the main body of the present invention, wherein the control unit is a signal processing control center. A sensor is mounted on the inner side of the door of the refrigerator and is connected to the control unit of the main body. When the door of the refrigerator is open, the sensor is triggered to transmit a sensor signal to the control unit to broadcast the voice. A timer is also connected to the control unit to active the apparatus at a predetermined time. In other words, a predetermined voice content is broadcasted. Thus, the reminding, warning, and encouraging effects are accomplished so as to act an interactive communication medium for family members.