We report the initial study of the reconfigurable antenna composed of graphene, in which a coplanar waveguide (CPW)-fed circular slot antenna is presented. The simple circular antenna made of copper is connected with the graphene slot by a short circuiting stub, where the graphene slot can be tuned by DC voltage bias. When the graphene acts the metallic conductor or the lossy dielectric with different DC bias setting, the effective length of the proposed antenna is changed, as well as the resonant frequency. The attractive properties of the proposed antenna can find its applications for future graphene multi Terabit wireless data transmission and transparent all-graphene sensing systems.