We present new photometric observations of the short period binary DY CVn. By using the Wilson-Devinney code of 2013 version, we found that DY CVn is a shallow contact binary (f = 13.2%) with a high mass ratio of q = 1.251. It is a W-subtype contact system where the more massive component is about 113 K cooler than the less massive one. From 44 available CCD times of light minimum collected from the references and 3 new ones in the present paper, the variation of the orbital period is studied. It is found that the 0 - C diagram shows a cyclic variation, and the most plausible explanation for this cyclic change is the light-travel time effect via a third body, since an outer third companion could play an important role for its formation by removing angular momentum from the central binary. (C) 2017 Elsevier B.V. All rights reserved.