Single-layer superconductors[1] have been the subject of considerable interests as they are ideal systems for the fundamental understanding of two-dimensional (2D) physics and for device applications.A few singlelayer superconductors are experimentally achieved (e.g.,FeSe,MoS2,and NbSe2[2-4]) in the field where either charge doping or tensile strain is often required to promote the superconductivity.An intrinsic singlelayer superconductor is highly demanded since no extra controlling efforts are needed for the superconductivity.In this issue,Gu et al.[5] theoretically proposed that a planar single-layer carbon sheet consisting of 4-and 8-membered rings (named as T-graphene) has a potential to be an intrinsic 2D superconductor with a predicted superconducting transition temperature (Tc) at ～20K.