An apparatus for displaying at least one virtual lane line based on an environmental condition and a method of controlling the same. The method includes recognizing an actual lane line of a vehicle traveling direction through at least one sensor, determining whether a head-up display (HUD) has been installed in a vehicle, upon determining that the HUD has been installed in the vehicle, displaying a first virtual lane line corresponding to the recognized actual lane line through the HUD and displaying a second virtual lane line corresponding to the recognized actual lane line on a road surface through a headlamp, and upon determining that the HUD has not been installed in the vehicle, displaying only a third virtual lane line corresponding to the recognized actual lane line through the headlamp.