An image display method for a rearview camera for displaying an image shot by a rearview camera mounted on a vehicle on a screen that can be viewed from a driver's seat, the method includes the step of displaying an auxiliary line image indicating the straight rear direction of the vehicle superimposed on the image shot by the vehicle on the screen. When the vehicle has approached the trailer within a predetermined range, an image from the rearview camera is converted to an image from a virtual overhead viewpoint then displayed on the screen. The driver easily back the vehicle to bring the hitch in the blind spot at the rear of the vehicle to coincide with a coupling member on the trailer while watching the screen display.