Abstract: Although many articles about the problem of the virtual object imaging were published, they neglect to argue in advance whether the virtual object possessing properties of imaging materials by optics, whether the theories of real objects imaging apply to the virtual objects imaging. All these articles take the virtual objects for the real objects directly, and by imaging methods of drawing diagram of the real objects. With the help of various examples to illustrate imaging methods of drawing diagram of the virtual objects, this paper proves through the conjugate connections between object and image, and the formula of virtual object imaging： virtual object is the object of imaging by optics, possessing all properties of optical imaging object. We can solve the image of virtual object and discuss the property of image by all theories and methods of real object imaging.

Key words: virtual object, property of virtual object, virtual object imaging formula