A mobile reproducing device comprising: reproducing means adapted to reproduce an audio signal and a video signal; main-body output means (2, 3) that is provided for a main body of the mobile reproducing device, and that is adapted to output a video signal and an audio signal reproduced by the reproducing means; storage means adapted to store a setting table in which control information associated with a device environmental condition is registered; and control means adapted to determine a device environmental condition, to acquire control information corresponding to the determined device environmental condition with reference to the setting table and to set volume levels in association with the acquired control information; wherein the control means is adapted to determine a state where the mobile reproducing device is coupled to an apparatus of a vehicle, and a state where the mobile reproducing device is not coupled to any apparatus, as the device environmental condition; characterized by cradle interface adapted to transmit a video signal and an audio signal reproduced by the reproducing means to the apparatus of the vehicle coupled to the mobile reproducing device or to a home AV system coupled to the mobile reproducing device; wherein the control means is adapted to determine a state where the mobile reproducing device is coupled to the home AV system as the device environmental condition and is adapted to determine whether the vehicle is running or in a stopped state for determining the device environmental condition, if the control means has determined that the mobile reproducing device is coupled to the apparatus of the vehicle; in the setting table, the environmental conditions are classified into four conditions, the four conditions being HANDY, CAR/STOP, CAR/RUN, and HOME, wherein the condition HANDY corresponding to the state where the mobile reproducing device is used alone; the condition CAR/STOP corresponding to the state where the mobile reproducing device is coupled to a vehicle AV system via a vehicle cradle and the car is in the stopped state; the condition CAR/RUN corresponding to the state where the mobile reproducing device is coupled to a vehicle AV system via the vehicle cradle and the car is running; and the condition HOME corresponding to the state where the mobile reproducing device is coupled to the home AV system via a home cradle; and wherein the control means is adapted to determine the condition that corresponds the determined state and to determine whether a video signal and an audio signal reproduced by the reproducing means have to be outputted by the main-body output means (2, 3) or have to be transmitted by the cradle interface in association with the control information assigned to the determined condition in the setting table. reproducing means adapted to reproduce an audio signal and a video signal; main-body output means (2, 3) that is provided for a main body of the mobile reproducing device, and that is adapted to output a video signal and an audio signal reproduced by the reproducing means; storage means adapted to store a setting table in which control information associated with a device environmental condition is registered; and control means adapted to determine a device environmental condition, to acquire control information corresponding to the determined device environmental condition with reference to the setting table and to set volume levels in association with the acquired control information; wherein the control means is adapted to determine a state where the mobile reproducing device is coupled to an apparatus of a vehicle, and a state where the mobile reproducing device is not coupled to any apparatus, as the device environmental condition; characterized by cradle interface adapted to transmit a video signal and an audio signal reproduced by the reproducing means to the apparatus of the vehicle coupled to the mobile reproducing device or to a home AV system coupled to the mobile reproducing device; wherein the control means is adapted to determine a state where the mobile reproducing device is coupled to the home AV system as the device environmental condition and is adapted to determine whether the vehicle is running or in a stopped state for determining the device environmental condition, if the control means has determined that the mobile reproducing device is coupled to the apparatus of the vehicle; in the setting table, the environmental conditions are classified into four conditions, the four conditions being HANDY, CAR/STOP, CAR/RUN, and HOME, wherein the condition HANDY corresponding to the state where the mobile reproducing device is used alone; the condition CAR/STOP corresponding to the state where the mobile reproducing device is coupled to a vehicle AV system via a vehicle cradle and the car is in the stopped state; the condition CAR/RUN corresponding to the state where the mobile reproducing device is coupled to a vehicle AV system via the vehicle cradle and the car is running; and the condition HOME corresponding to the state where the mobile reproducing device is coupled to the home AV system via a home cradle; and wherein the control means is adapted to determine the condition that corresponds the determined state and to determine whether a video signal and an audio signal reproduced by the reproducing means have to be outputted by the main-body output means (2, 3) or have to be transmitted by the cradle interface in association with the control information assigned to the determined condition in the setting table.