An embodiment of the preset invention includes a light source; a lens in which the first reflecting unit is provided on a partial area of a front surface thereof; a light reducer which reduces the size of the cross section perpendicular to the optical axis of light emitted from the light source and then emits toward the first reflecting unit; and a reflective fluorescent body which is disposed on the rear side of the lens and converts wavelength of light reflected from the first reflecting unit and then reflects the light into the lens, and thus the number of components the lighting device for a vehicle can be minimized and the lighting device for a vehicle can be made compact.