A virtual image displaying system is disclosed and includes: a projector, an optical relaying device, a reflective mirror and a slit array. The projector has a main body and a projection lens connecting to the main body. The main body outputs a light beam by the projection lens. The optical relaying device faces the projection lens and is disposed under the projection lens. The reflective mirror is inclined relative to and disposed above the optical relaying device. The slit array is inclined relative to and disposed in front of the reflective mirror. The projection lens is further disposed between the reflective mirror and the slit array. Therefore, the virtual image displaying system has a compact configuration of components.
