AR seems to be one of the most advanced and near-future technologies that produce new experiences and values that have never been before. However, both AR and art have a common means of engaging the senses. Thus, the problem of where the borderline between AR and art exists should come into question. In order to consider how AR will have an influence on the definition and the significance of art, this study analyses real and fictional elements in AR and art. AR requires the physical field where sensory information mediated by computer is projected. Consequently, viewers perceive the mixed image of real things and those not existing before eyes, that is fiction. Art also needs a real environment where the fictional world is opened. Though art and AR have something in common, there are crucial differences between them. AR technologies include the firm aim of erasing fictional elements that remain as ever in spite of their accurate representation. On the other hand, art attempts to preserve a fictional area within the real world. From the comparison of AR and art, it will come to light that whether there is the frame or not plays an important role in deciding what is art or what is reality. While AR reduces fictionality from a multi-layered scene to enrich a real experience, art cuts fiction from a present scene to idealize the real world. In this way, they constitute a dialectical circle and mediate new reality through fictional images from the reverse direction.