A vehicle headlamp system comprising: a headlamp comprising a plurality of control devices (4, 5, 7); and an ECU configured to control the control devices (4, 5, 7) respectively, wherein each of the control devices (4, 5, 7) is configured to control and change a light irradiation condition of the headlamp, upon control by the ECU, wherein the ECU is configured to store vehicle constants, error code information and initialization information corresponding to different types of vehicles respectively, and to control the control devices (4, 5, 7) in accordance with the stored information, wherein, when a vehicle type is changed, the ECU is configured to select at least one of the vehicle constants that corresponds to the changed vehicle type, to clear the stored error code information and the initialization information after selecting the at least one of the vehicle constants, to store initialization information that corresponds to the changed vehicle type in accordance with the selected vehicle constant, and to initialize the control devices (4, 5, 7) in accordance with the stored initialization information, and wherein the ECU is configured to recognize dependencies between the control devices (4, 5, 7) and, if a first control device of the control devices (4, 5, 7) is recognized as being independent on other control devices (4, 5, 7), the ECU executes normal control by the first control device when the initialization of the first control device is not required, and the ECU executes the normal control by the first control device directly after initializing the first control device if the initialization of the first control device is required, characterised in that if a second control device of the control devices (4, 5, 7) is recognized as being dependent on another of the control devices (4, 5, 7), the ECU stops normal control by the second control device until initialization of the other of the control devices (4, 5, 7) is completed. wherein the control devices (4, 5, 7) comprise: a leveling device configured to control and change a light irradiation direction of the headlamp in up and down directions; and a swiveling device configured to control and change the light irradiation direction in right and left directions, wherein the ECU is configured to recognize the leveling device as the first control device, and to recognize the swiveling device as the second control device that is dependent on the leveling device such that normal control by the swiveling device is stopped until initialization of the leveling device is completed. a headlamp comprising a plurality of control devices (4, 5, 7); and an ECU configured to control the control devices (4, 5, 7) respectively, wherein each of the control devices (4, 5, 7) is configured to control and change a light irradiation condition of the headlamp, upon control by the ECU, wherein the ECU is configured to store vehicle constants, error code information and initialization information corresponding to different types of vehicles respectively, and to control the control devices (4, 5, 7) in accordance with the stored information, wherein, when a vehicle type is changed, the ECU is configured to select at least one of the vehicle constants that corresponds to the changed vehicle type, to clear the stored error code information and the initialization information after selecting the at least one of the vehicle constants, to store initialization information that corresponds to the changed vehicle type in accordance with the selected vehicle constant, and to initialize the control devices (4, 5, 7) in accordance with the stored initialization information, and wherein the ECU is configured to recognize dependencies between the control devices (4, 5, 7) and, if a first control device of the control devices (4, 5, 7) is recognized as being independent on other control devices (4, 5, 7), the ECU executes normal control by the first control device when the initialization of the first control device is not required, and the ECU executes the normal control by the first control device directly after initializing the first control device if the initialization of the first control device is required, characterised in that if a second control device of the control devices (4, 5, 7) is recognized as being dependent on another of the control devices (4, 5, 7), the ECU stops normal control by the second control device until initialization of the other of the control devices (4, 5, 7) is completed. wherein the control devices (4, 5, 7) comprise: a leveling device configured to control and change a light irradiation direction of the headlamp in up and down directions; and a swiveling device configured to control and change the light irradiation direction in right and left directions, wherein the ECU is configured to recognize the leveling device as the first control device, and to recognize the swiveling device as the second control device that is dependent on the leveling device such that normal control by the swiveling device is stopped until initialization of the leveling device is completed. a leveling device configured to control and change a light irradiation direction of the headlamp in up and down directions; and a swiveling device configured to control and change the light irradiation direction in right and left directions, wherein the ECU is configured to recognize the leveling device as the first control device, and to recognize the swiveling device as the second control device that is dependent on the leveling device such that normal control by the swiveling device is stopped until initialization of the leveling device is completed.